CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total		Cumulative Effect, Period of Adoption, Adjustment	Class A and Class B Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit	[1]	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	[1]
Balance, Beginning at Jan. 31, 2018	$ 14,968		$ 39,802	$ 13	$ 1,054,932	$ (1,177)	$ 288	$ (1,039,088)		$ 39,802
Balance, Beginning, Shares at Jan. 31, 2018				137,317,000
Issuance of common stock upon stock option exercises	16,326				16,326
Issuance of common stock upon stock option exercises (in shares)				1,980,000
Issuance of common stock in connection with acquisitions	1,053				1,053
Issuance of common stock in connection with acquisitions (in shares)				40,000
Issuance of common stock in connection with charitable donations	243				243
Issuance of common stock in connection with charitable donations (in shares)				12,000
Stock-based compensation related to stock awards	115,852				115,852
Vesting of restricted stock units, net of shares withheld for employee payroll taxes	1			$ 1
Vesting of restricted stock units, net of shares withheld for employee payroll taxes (in shares)				3,345,000
Employee payroll taxes withheld related to vesting of restricted stock units	$ (43,824)				(43,824)
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201409Member
Common stock issued under employee stock purchase plan	$ 21,861				21,861
Common stock issued under employee stock purchase plan (in shares)				1,617,000
Other comprehensive loss	(265)	[2]					(265)
Net loss	(134,612)	[2]						(134,612)
Balance, Ending at Jan. 31, 2019	31,405			$ 14	1,166,443	(1,177)	23	(1,133,898)
Balance, Ending, Shares at Jan. 31, 2019				144,311,000
Issuance of common stock upon stock option exercises	$ 5,965				5,965
Issuance of common stock upon stock option exercises (in shares)	659,348			659,000
Stock-based compensation related to stock awards	$ 149,567				149,567
Vesting of restricted stock units, net of shares withheld for employee payroll taxes	1			$ 1
Vesting of restricted stock units, net of shares withheld for employee payroll taxes (in shares)				4,167,000
Employee payroll taxes withheld related to vesting of restricted stock units	(43,328)				(43,328)
Common stock issued under employee stock purchase plan	23,425				23,425
Common stock issued under employee stock purchase plan (in shares)				1,474,000
Other comprehensive loss	(330)						(330)
Net loss	(144,348)							(144,348)
Balance, Ending at Jan. 31, 2020	22,357			$ 15	1,302,072	(1,177)	(307)	(1,278,246)
Balance, Ending, Shares at Jan. 31, 2020				150,611,000
Issuance of common stock upon stock option exercises	$ 10,261				10,261
Issuance of common stock upon stock option exercises (in shares)	1,994,667			1,995,000
Stock-based compensation related to stock awards	$ 151,873				151,873
Vesting of restricted stock units, net of shares withheld for employee payroll taxes	1			$ 1
Vesting of restricted stock units, net of shares withheld for employee payroll taxes (in shares)				5,100,000
Employee payroll taxes withheld related to vesting of restricted stock units	(48,761)				(48,761)
Common stock issued under employee stock purchase plan	18,595				18,595
Common stock issued under employee stock purchase plan (in shares)				2,145,000
Equity component of convertible senior notes, net of issuance costs	68,576				68,576
Purchase of capped calls related to convertible senior notes	(27,773)				(27,773)
Other comprehensive loss	(631)						(631)
Net loss	(43,433)							(43,433)
Balance, Ending at Jan. 31, 2021	$ 151,065			$ 16	$ 1,474,843	$ (1,177)	$ (938)	$ (1,321,679)
Balance, Ending, Shares at Jan. 31, 2021				159,851,000

[1] We adopted ASC Topic 842, effective February 1, 2019, utilizing the modified retrospective method. The reported results for fiscal year 2020 onwards reflect the application of ASC 842 while the reported results for fiscal years presented prior to adoption are not adjusted and continue to be reported under ASC Topic 840.

[2] As reported and disclosed under ASC Topic 840