Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Income Tax Disclosure [Abstract]
Provision for income taxes at statutory rate	$ (18,453)	$ (29,354)	$ (29,129)
State income taxes, net of federal benefit	0	25	245
Foreign earnings at different rates	1,994	207	97
Research and other credits	(9,373)	(1,534)	(3,769)
Stock-based compensation	(140,489)	(43,477)	2,414
Non-deductible expenses	2,212	1,773	1,833
Change in unrecognized tax benefits	0	(2,659)	0
Valuation allowance	168,869	77,016	29,676
Provision for income taxes	$ 4,760	$ 1,997	$ 1,367

Effective Income Tax Reconciliation, Increase (Decrease) in Unrecognized Tax Benefits

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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 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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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from 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 tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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