Net Income Per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Earnings Per Share, Basic [Abstract]
Net income									$ 672,316	$ 25,305	$ 7,584
Less: undistributed earnings attributable to participating securities									(789)	(3,555)	(7,584)
Net income attributable to common stockholders	$ 260,393	$ 198,440	$ 185,742	$ 27,036	$ 15,313	$ 2,207	$ 5,521	$ 198	$ 671,527	$ 21,750	$ 0
Earnings Per Share, Diluted [Abstract]
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic (in shares)									283,853,654	233,641,336	84,483,094
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, diluted (in shares)									298,127,669	254,298,014	116,005,681
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)	$ 0.91	$ 0.70	$ 0.66	$ 0.10	$ 0.06	$ 0.01	$ 0.02	$ 0.00	$ 2.37	$ 0.09	$ 0.00
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)	$ 0.87	$ 0.66	$ 0.63	$ 0.09	$ 0.05	$ 0.01	$ 0.02	$ 0.00	$ 2.25	$ 0.09	$ 0.00
Class A Common Stock
Earnings Per Share, Basic [Abstract]
Net income									$ 432,968	$ 5,450	$ 0
Less: undistributed earnings attributable to participating securities									0	0	0
Net income attributable to common stockholders									432,968	5,450	0
Reallocation of net income attributable to common stockholders									(14,321)	(439)	0
Net income attributable to common stockholders, diluted									$ 418,647	$ 5,011	$ 0
Earnings Per Share, Diluted [Abstract]
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic (in shares)									183,015,245	58,541,269	0
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, diluted (in shares)									185,860,412	58,583,874	0
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)									$ 2.37	$ 0.09	$ 0
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)									$ 2.25	$ 0.09	$ 0
Class B Common Stock
Earnings Per Share, Basic [Abstract]
Net income									$ 239,348	$ 19,855	$ 7,584
Less: undistributed earnings attributable to participating securities									(789)	(3,555)	(7,584)
Net income attributable to common stockholders									238,559	16,300	0
Reallocation of net income attributable to common stockholders									14,321	439	0
Net income attributable to common stockholders, diluted									$ 252,880	$ 16,739	$ 0
Earnings Per Share, Diluted [Abstract]
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic (in shares)									100,838,409	175,100,067	84,483,094
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, diluted (in shares)									112,267,257	195,714,140	116,005,681
Net income (loss) per share attributable to common stockholders, basic (in dollars per share)									$ 2.37	$ 0.09	$ 0.00
Net income (loss) per share attributable to common stockholders, diluted (in dollars per share)									$ 2.25	$ 0.09	$ 0.00