Fair Value Measurements - Schedule of Fair Value of Financial Assets (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | |
Jun. 30, 2022 | Jun. 30, 2021 | Jun. 30, 2022 | Jun. 30, 2021 | Dec. 31, 2021 |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | $ 278,396 | | $ 278,396 | | $ 221,382 |
Marketable Securities, Fair Value | 2,378,899 | | 2,378,899 | | 2,742,571 |
Total Financial Assets, Fair Value | 2,691,310 | | 2,691,310 | | 3,013,121 |
Unrealized gain (loss) on equity investments | (5,084) | $ 0 | 23,413 | $ 0 | |
Fair Value to Amortized Cost | | | | | |
Amortized Cost | 2,415,312 | | 2,415,312 | | 2,748,697 |
Unrealized Gains | 7 | | 7 | | 144 |
Unrealized Losses | (36,420) | | (36,420) | | (6,270) |
Fair Value | 2,378,899 | | 2,378,899 | | 2,742,571 |
Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 274,754 | | 274,754 | | 221,382 |
Total Financial Assets, Fair Value | 1,377,823 | | 1,377,823 | | 1,283,429 |
Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 3,642 | | 3,642 | | 0 |
Total Financial Assets, Fair Value | 1,313,487 | | 1,313,487 | | 1,729,692 |
Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 0 | | 0 | | 0 |
Total Financial Assets, Fair Value | 0 | | 0 | | 0 |
Commercial paper | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 18,462 | | 18,462 | | 141,274 |
Fair Value to Amortized Cost | | | | | |
Amortized Cost | 18,462 | | 18,462 | | 141,274 |
Unrealized Gains | 0 | | 0 | | 0 |
Unrealized Losses | 0 | | 0 | | 0 |
Fair Value | 18,462 | | 18,462 | | 141,274 |
Commercial paper | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Commercial paper | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 18,462 | | 18,462 | | 141,274 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 18,462 | | 18,462 | | 141,274 |
Commercial paper | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Certificate of deposits | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 13,030 | | 13,030 | | 44,931 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 13,030 | | 13,030 | | 44,931 |
Certificate of deposits | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Certificate of deposits | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 13,030 | | 13,030 | | 44,931 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 13,030 | | 13,030 | | 44,931 |
Certificate of deposits | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
U.S. government notes | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,082,084 | | 1,082,084 | | 1,057,810 |
Fair Value to Amortized Cost | | | | | |
Amortized Cost | 1,098,360 | | 1,098,360 | | 1,060,716 |
Unrealized Gains | 0 | | 0 | | 3 |
Unrealized Losses | (16,276) | | (16,276) | | (2,909) |
Fair Value | 1,082,084 | | 1,082,084 | | 1,057,810 |
U.S. government notes | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,082,084 | | 1,082,084 | | 1,057,810 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 1,082,084 | | 1,082,084 | | 1,057,810 |
U.S. government notes | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
U.S. government notes | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Corporate bonds | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,066,585 | | 1,066,585 | | 1,252,226 |
Fair Value to Amortized Cost | | | | | |
Amortized Cost | 1,083,803 | | 1,083,803 | | 1,255,149 |
Unrealized Gains | 6 | | 6 | | 105 |
Unrealized Losses | (17,224) | | (17,224) | | (3,028) |
Fair Value | 1,066,585 | | 1,066,585 | | 1,252,226 |
Corporate bonds | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Corporate bonds | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,066,585 | | 1,066,585 | | 1,252,226 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 1,066,585 | | 1,066,585 | | 1,252,226 |
Corporate bonds | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Agency securities | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 211,768 | | 211,768 | | 291,261 |
Fair Value to Amortized Cost | | | | | |
Amortized Cost | 214,687 | | 214,687 | | 291,558 |
Unrealized Gains | 1 | | 1 | | 36 |
Unrealized Losses | (2,920) | | (2,920) | | (333) |
Fair Value | 211,768 | | 211,768 | | 291,261 |
Agency securities | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Agency securities | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 211,768 | | 211,768 | | 291,261 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 211,768 | | 211,768 | | 291,261 |
Agency securities | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Marketable equity securities | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 16,727 | | 16,727 | | 0 |
Fair value of securities reclassified | | | 8,300 | | |
Unrealized gain (loss) on equity investments | (5,100) | | 8,400 | | |
Fair Value to Amortized Cost | | | | | |
Fair Value | 16,727 | | 16,727 | | 0 |
Marketable equity securities | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 16,727 | | 16,727 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 16,727 | | 16,727 | | 0 |
Marketable equity securities | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Marketable equity securities | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Marketable Securities | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 2,408,656 | | 2,408,656 | | 2,787,502 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 2,408,656 | | 2,408,656 | | 2,787,502 |
Marketable Securities | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,098,811 | | 1,098,811 | | 1,057,810 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 1,098,811 | | 1,098,811 | | 1,057,810 |
Marketable Securities | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 1,309,845 | | 1,309,845 | | 1,729,692 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 1,309,845 | | 1,309,845 | | 1,729,692 |
Marketable Securities | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Marketable Securities, Fair Value | 0 | | 0 | | 0 |
Fair Value to Amortized Cost | | | | | |
Fair Value | 0 | | 0 | | 0 |
Money market funds - restricted | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Other Assets, Fair Value | 4,258 | | 4,258 | | 4,237 |
Money market funds - restricted | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Other Assets, Fair Value | 4,258 | | 4,258 | | 4,237 |
Money market funds - restricted | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Other Assets, Fair Value | 0 | | 0 | | 0 |
Money market funds - restricted | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Other Assets, Fair Value | 0 | | 0 | | 0 |
Money market funds | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 274,754 | | 274,754 | | 221,382 |
Money market funds | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 274,754 | | 274,754 | | 221,382 |
Money market funds | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 0 | | 0 | | 0 |
Money market funds | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 0 | | 0 | | 0 |
Commercial paper | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 3,642 | | 3,642 | | 0 |
Commercial paper | Level I | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 0 | | 0 | | 0 |
Commercial paper | Level II | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | 3,642 | | 3,642 | | 0 |
Commercial paper | Level III | | | | | |
Assets, Fair Value Disclosure [Abstract] | | | | | |
Cash Equivalents, Fair Value | $ 0 | | $ 0 | | $ 0 |