CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings
Beginning balance (in shares) at Jan. 31, 2020		278,731,143
Beginning balance at Jan. 31, 2020	$ 833,943	$ 277	$ 832,705	$ 809	$ 152
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		3,232,991
Issuance of common stock upon exercise of stock options	9,725	$ 3	9,722
Issuance of common stock upon release of restricted stock units (in shares)		27,877
Charitable donation of common stock	1,000		1,000
Stock-based compensation expense	28,810		28,810
Other comprehensive income (loss)	1,078			1,078
Net income	27,075				27,075
Ending balance (in shares) at Apr. 30, 2020		281,992,011
Ending balance at Apr. 30, 2020	901,631	$ 280	872,237	1,887	27,227
Beginning balance (in shares) at Jan. 31, 2021		293,549,223
Beginning balance at Jan. 31, 2021	$ 3,860,767	$ 292	3,187,168	839	672,468
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	751,686	751,686
Issuance of common stock upon exercise of stock options	$ 3,476	$ 1	3,475
Issuance of common stock upon release of restricted stock units (in shares)		211,036
Stock-based compensation expense	101,598		101,598
Other comprehensive income (loss)	(639)			(639)
Net income	227,531				227,531
Ending balance (in shares) at Apr. 30, 2021		294,511,945
Ending balance at Apr. 30, 2021	$ 4,192,733	$ 293	$ 3,292,241	$ 200	$ 899,999