Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Net loss before tax	$ (578,485)	$ (357,937)	$ (213,256)
Statutory combined U.S. federal and state tax rate (as a percent)	21.00%	21.00%	21.00%
Tax computed at federal statutory rate	$ (121,482)	$ (75,167)	$ (44,784)
State income taxes, net of federal benefit	(4,657)	(13,490)	0
Effect of change in valuation allowance	150,487	110,985	52,719
Non-deductible share-based compensation	4,783	2,724	1,810
Tax deductions for share-based compensation	(17,243)	(17,991)	(6,917)
Tax credits	(30,289)	(15,672)	(8,621)
Foreign withholding taxes	3,299	0	0
Change in tax rate	2,972	0	0
Unrecognized tax benefits	7,573	3,857	2,143
Non-deductible officers’ compensation	8,318	4,697	3,527
Other differences	(462)	57	123
Income tax expense	$ 3,299	$ 0	$ 0

Effective Income Tax Rate Reconciliation, Combined Federal and State Statutory Income Tax Rate, Percent

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Effective Income Tax Rate Reconciliation, Non-Deductible Officers' Compensation, Amount

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to increase (decrease) in the valuation allowance for deferred tax assets.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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