CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated other comprehensive loss	Accumulated deficit
Cumulative-effect adjustment from adoption of ASU | Accounting Standards Update 2016-02					$ 7,241
Balance, beginning of period at Jan. 31, 2019		$ 149	$ 2,754,858	$ (2,506)	(1,232,044)
Vesting of restricted stock units		1
Stock-based compensation			123,063
Capitalized software development costs			0
Issuance of common stock upon exercise of options			359
Vesting of early exercised options	$ 0		0
Taxes paid related to net share settlement of equity awards			(69,007)
Unrealized gain from investments (net of tax)				332
Net change in cumulative translation adjustments	(991)			(991)
Net loss	(155,429)				(155,429)
Balance, end of period at Apr. 30, 2019	1,426,026	150	2,809,273	(3,165)	(1,380,232)
Cumulative-effect adjustment from adoption of ASU | Accounting Standards Update 2016-02					0
Balance, beginning of period at Jan. 31, 2020	1,999,429	157	3,566,055	(5,312)	(1,561,471)
Vesting of restricted stock units		1
Stock-based compensation			158,818
Capitalized software development costs			1,776
Issuance of common stock upon exercise of options			1,418
Vesting of early exercised options	56		56
Taxes paid related to net share settlement of equity awards			(49,228)
Unrealized gain from investments (net of tax)				2,685
Net change in cumulative translation adjustments	679			679
Net loss	(305,579)				(305,579)
Balance, end of period at Apr. 30, 2020	$ 1,810,055	$ 158	$ 3,678,895	$ (1,948)	$ (1,867,050)