Net Income per Share Attributable to Common Stockholders - Numerators and Denominators of the Basic and Diluted EPS Computations for Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands | 3 Months Ended |
Apr. 30, 2019 | Apr. 30, 2018 |
Schedule Of Earnings Per Share Basic And Diluted [Line Items] | | |
Net income | $ 73,449 | $ 44,310 |
Weighted average shares used in computing net income per share attributable to common stockholders, basic | 146,708 | 142,777 |
Net income per share attributable to common stockholders, basic | $ 0.50 | $ 0.31 |
Reallocation as a result of conversion of Class B to Class A common stock: | | |
Weighted average shares used in computing net income per share attributable to common stockholders, diluted | 157,910 | 154,935 |
Net income per share attributable to common stockholders, diluted | $ 0.47 | $ 0.29 |
Class A common stock [Member] | | |
Schedule Of Earnings Per Share Basic And Diluted [Line Items] | | |
Net income | $ 63,652 | |
Net income attributable to common stockholders, basic | $ 63,652 | |
Weighted average shares used in computing net income per share attributable to common stockholders, basic | 127,139 | |
Net income per share attributable to common stockholders, basic | $ 0.50 | |
Net income attributable to common stockholders, basic | $ 63,652 | |
Reallocation as a result of conversion of Class B to Class A common stock: | | |
Net income attributable to common stockholders, basic | 9,797 | |
Net income attributable to common stockholders, diluted | $ 73,449 | |
Conversion of Class B to Class A common stock | 19,569 | |
Effect of potentially dilutive common shares | 11,202 | |
Weighted average shares used in computing net income per share attributable to common stockholders, diluted | 157,910 | |
Net income per share attributable to common stockholders, diluted | $ 0.47 | |
Class A common stock [Member] | As adjusted [Member] | | |
Schedule Of Earnings Per Share Basic And Diluted [Line Items] | | |
Net income | | $ 36,830 |
Net income attributable to common stockholders, basic | | $ 36,830 |
Weighted average shares used in computing net income per share attributable to common stockholders, basic | | 118,675 |
Net income per share attributable to common stockholders, basic | | $ 0.31 |
Net income attributable to common stockholders, basic | | $ 36,830 |
Reallocation as a result of conversion of Class B to Class A common stock: | | |
Net income attributable to common stockholders, basic | | 7,480 |
Net income attributable to common stockholders, diluted | | $ 44,310 |
Conversion of Class B to Class A common stock | | 24,102 |
Effect of potentially dilutive common shares | | 12,158 |
Weighted average shares used in computing net income per share attributable to common stockholders, diluted | | 154,935 |
Net income per share attributable to common stockholders, diluted | | $ 0.29 |
Class B common stock [Member] | | |
Schedule Of Earnings Per Share Basic And Diluted [Line Items] | | |
Net income | $ 9,797 | |
Net income attributable to common stockholders, basic | $ 9,797 | |
Weighted average shares used in computing net income per share attributable to common stockholders, basic | 19,569 | |
Net income per share attributable to common stockholders, basic | $ 0.50 | |
Net income attributable to common stockholders, basic | $ 9,797 | |
Reallocation as a result of conversion of Class B to Class A common stock: | | |
Reallocation of net income to Class B common stock | 4,516 | |
Net income attributable to common stockholders, diluted | $ 14,313 | |
Effect of potentially dilutive common shares | 11,202 | |
Weighted average shares used in computing net income per share attributable to common stockholders, diluted | 30,771 | |
Net income per share attributable to common stockholders, diluted | $ 0.47 | |
Class B common stock [Member] | As adjusted [Member] | | |
Schedule Of Earnings Per Share Basic And Diluted [Line Items] | | |
Net income | | $ 7,480 |
Net income attributable to common stockholders, basic | | $ 7,480 |
Weighted average shares used in computing net income per share attributable to common stockholders, basic | | 24,102 |
Net income per share attributable to common stockholders, basic | | $ 0.31 |
Net income attributable to common stockholders, basic | | $ 7,480 |
Reallocation as a result of conversion of Class B to Class A common stock: | | |
Reallocation of net income to Class B common stock | | 2,890 |
Net income attributable to common stockholders, diluted | | $ 10,370 |
Effect of potentially dilutive common shares | | 12,158 |
Weighted average shares used in computing net income per share attributable to common stockholders, diluted | | 36,260 |
Net income per share attributable to common stockholders, diluted | | $ 0.29 |