Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financial Assets:
Marketable Securities:	$ 1,545,341	$ 1,283,473
Commercial paper
Financial Assets:
Marketable Securities:	356,273	151,356
Certificates of deposit
Financial Assets:
Marketable Securities:	173,530	14,569
U.S. government treasury securities
Financial Assets:
Marketable Securities:	119,878	77,442
U.S. government agency securities
Financial Assets:
Marketable Securities:	89,552
Non-U.S. government securities
Financial Assets:
Marketable Securities:		8,054
Fair Value, Recurring
Financial Assets:
Total financial assets	1,850,736	1,525,044
Fair Value, Recurring | Corporate debt securities
Financial Assets:
Marketable Securities:	806,108	1,032,052
Fair Value, Recurring | Commercial paper
Financial Assets:
Marketable Securities:	356,273	151,356
Fair Value, Recurring | Certificates of deposit
Financial Assets:
Marketable Securities:	173,530	14,569
Fair Value, Recurring | U.S. government treasury securities
Financial Assets:
Marketable Securities:	119,878	77,442
Fair Value, Recurring | U.S. government agency securities
Financial Assets:
Marketable Securities:	89,552
Fair Value, Recurring | Non-U.S. government securities
Financial Assets:
Marketable Securities:		8,054
Fair Value, Recurring | Money market funds
Financial Assets:
Cash equivalents:	302,902	241,571
Fair Value, Recurring | Corporate debt securities
Financial Assets:
Cash equivalents:	2,493
Fair Value, Recurring | Level 1
Financial Assets:
Total financial assets	302,902	241,571
Fair Value, Recurring | Level 1 | Corporate debt securities
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 1 | Commercial paper
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 1 | Certificates of deposit
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 1 | U.S. government treasury securities
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 1 | U.S. government agency securities
Financial Assets:
Marketable Securities:	0
Fair Value, Recurring | Level 1 | Non-U.S. government securities
Financial Assets:
Marketable Securities:		0
Fair Value, Recurring | Level 1 | Money market funds
Financial Assets:
Cash equivalents:	302,902	241,571
Fair Value, Recurring | Level 1 | Corporate debt securities
Financial Assets:
Cash equivalents:	0
Fair Value, Recurring | Level 2
Financial Assets:
Total financial assets	1,547,834	1,283,473
Fair Value, Recurring | Level 2 | Corporate debt securities
Financial Assets:
Marketable Securities:	806,108	1,032,052
Fair Value, Recurring | Level 2 | Commercial paper
Financial Assets:
Marketable Securities:	356,273	151,356
Fair Value, Recurring | Level 2 | Certificates of deposit
Financial Assets:
Marketable Securities:	173,530	14,569
Fair Value, Recurring | Level 2 | U.S. government treasury securities
Financial Assets:
Marketable Securities:	119,878	77,442
Fair Value, Recurring | Level 2 | U.S. government agency securities
Financial Assets:
Marketable Securities:	89,552
Fair Value, Recurring | Level 2 | Non-U.S. government securities
Financial Assets:
Marketable Securities:		8,054
Fair Value, Recurring | Level 2 | Money market funds
Financial Assets:
Cash equivalents:	0	0
Fair Value, Recurring | Level 2 | Corporate debt securities
Financial Assets:
Cash equivalents:	2,493
Fair Value, Recurring | Level 3
Financial Assets:
Total financial assets	0	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 3 | Commercial paper
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 3 | Certificates of deposit
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 3 | U.S. government treasury securities
Financial Assets:
Marketable Securities:	0	0
Fair Value, Recurring | Level 3 | U.S. government agency securities
Financial Assets:
Marketable Securities:	0
Fair Value, Recurring | Level 3 | Non-U.S. government securities
Financial Assets:
Marketable Securities:		0
Fair Value, Recurring | Level 3 | Money market funds
Financial Assets:
Cash equivalents:	0	$ 0
Fair Value, Recurring | Level 3 | Corporate debt securities
Financial Assets:
Cash equivalents:	$ 0