Net Income Per Share Attributable to Common Stockholders - Summary of Potential Shares of Common Stock Excluded from Computation of Diluted Net Income Per Share Attributable to Common Stockholders (Details) - shares		3 Months Ended		6 Months Ended
	Jul. 31, 2020	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	405,156	121,592	293,909	616,924	149,390
Class B Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		0	0		0
Outstanding stock options | Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		0	116,649	0	59,291
Outstanding stock options | Class B Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		0	0	0	0
Unvested RSUs | Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		85,596	153,751	598,728	78,150
Unvested RSUs | Class B Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		0	0	0	0
Purchase rights committed under the ESPP | Class A Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		35,996	23,509	18,196	11,949
Purchase rights committed under the ESPP | Class B Common Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		0	0	0	0