Net Income Per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 30, 2020	Apr. 30, 2019
Numerator:
Net income (loss)	$ 27,075	$ 2,214
Net income attributable to common stockholders	$ 27,036	$ 198
Denominator:
Weighted-average shares used in computing net income per share attributable to common stockholders, basic (in shares)	279,891,111	109,708,898
Weighted-average shares used in computing net income per share attributable to common stockholders, diluted (in shares)	295,184,958	136,428,379
Net income per share attributable to common stockholders, basic (in dollars per share)	$ 0.10	$ 0.00
Net income per share attributable to common stockholders, diluted (in dollars per share)	$ 0.09	$ 0.00
Class A Common Stock
Numerator:
Net income (loss)	$ 14,007	$ 15
Less: undistributed earnings attributable to participating securities	0	0
Net income attributable to common stockholders	14,007	15
Reallocation of net income attributable to common stockholders	(591)	(3)
Net income (loss) attributable to common stockholders, diluted	$ 13,416	$ 12
Denominator:
Weighted-average shares used in computing net income per share attributable to common stockholders, basic (in shares)	145,004,142	8,393,169
Weighted-average shares used in computing net income per share attributable to common stockholders, diluted (in shares)	146,472,265	8,393,391
Net income per share attributable to common stockholders, basic (in dollars per share)	$ 0.10	$ 0.00
Net income per share attributable to common stockholders, diluted (in dollars per share)	$ 0.09	$ 0.00
Class B Common Stock
Numerator:
Net income (loss)	$ 13,068	$ 2,199
Less: undistributed earnings attributable to participating securities	(39)	(2,016)
Net income attributable to common stockholders	13,029	183
Reallocation of net income attributable to common stockholders	591	3
Net income (loss) attributable to common stockholders, diluted	$ 13,620	$ 186
Denominator:
Weighted-average shares used in computing net income per share attributable to common stockholders, basic (in shares)	134,886,969	101,315,729
Weighted-average shares used in computing net income per share attributable to common stockholders, diluted (in shares)	148,712,693	128,034,988
Net income per share attributable to common stockholders, basic (in dollars per share)	$ 0.10	$ 0.00
Net income per share attributable to common stockholders, diluted (in dollars per share)	$ 0.09	$ 0.00