Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands | Total | Class A Common Stock | Class B Common Stock | Common StockClass A Common Stock | Common StockClass B Common Stock | Additional Paid-in Capital | Accumulated Other Comprehensive Income | Accumulated Deficit |
Convertible preferred stock, beginning balance (shares) at Jan. 31, 2018 | 14,098,937 | | | | | | | |
Convertible preferred stock, beginning balance at Jan. 31, 2018 | $ 693,158 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Apr. 30, 2018 | 14,098,937 | | | | | | | |
Convertible preferred stock, ending balance at Apr. 30, 2018 | $ 693,158 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Jan. 31, 2018 | | | | 0 | 1,638,648 | | | |
Stockholders (deficit) equity, beginning balance at Jan. 31, 2018 | (721,964) | | | $ 0 | $ 2 | $ 35,301 | $ 506 | $ (757,773) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Exercise of stock options (shares) | | | | | 16,221 | | | |
Exercise of stock options | 212 | | | | | 212 | | |
Stock-based compensation expense | 2,076 | | | | | 2,076 | | |
Other comprehensive income (loss) | (37) | | | | | | (37) | |
Net loss | (45,507) | | | | | | | (45,507) |
Stockholders (deficit) equity, ending balance (shares) at Apr. 30, 2018 | | | | 0 | 1,654,869 | | | |
Stockholders (deficit) equity, ending balance at Apr. 30, 2018 | $ (765,220) | | | $ 0 | $ 2 | 37,589 | 469 | (803,280) |
Convertible preferred stock, beginning balance (shares) at Jan. 31, 2018 | 14,098,937 | | | | | | | |
Convertible preferred stock, beginning balance at Jan. 31, 2018 | $ 693,158 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Oct. 31, 2018 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Oct. 31, 2018 | $ 0 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Jan. 31, 2018 | | | | 0 | 1,638,648 | | | |
Stockholders (deficit) equity, beginning balance at Jan. 31, 2018 | (721,964) | | | $ 0 | $ 2 | 35,301 | 506 | (757,773) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Net loss | (124,436) | $ (14,356) | $ (110,080) | | | | | |
Stockholders (deficit) equity, ending balance (shares) at Oct. 31, 2018 | | | | 3,263,659 | 23,074,189 | | | |
Stockholders (deficit) equity, ending balance at Oct. 31, 2018 | $ 66,859 | | | $ 3 | $ 23 | 948,686 | 356 | (882,209) |
Convertible preferred stock, beginning balance (shares) at Apr. 30, 2018 | 14,098,937 | | | | | | | |
Convertible preferred stock, beginning balance at Apr. 30, 2018 | $ 693,158 | | | | | | | |
Increase (Decrease) in Convertible Preferred Stock [Roll Forward] | | | | | | | | |
Conversion of convertible preferred stock (shares) | (14,098,937) | | | | | | | |
Conversion of convertible preferred stock | $ (693,158) | | | | | | | |
Convertible preferred stock, ending balance (shares) at Jul. 31, 2018 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Jul. 31, 2018 | $ 0 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Apr. 30, 2018 | | | | 0 | 1,654,869 | | | |
Stockholders (deficit) equity, beginning balance at Apr. 30, 2018 | (765,220) | | | $ 0 | $ 2 | 37,589 | 469 | (803,280) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Initial public offering, net of offering costs of $4,201 (shares) | | | | | 10,580,000 | | | |
Initial public offering, net of offering costs of $4,201 | 202,426 | | | | $ 10 | 202,416 | | |
Initial public offering costs | 4,201 | | | | | | | |
Conversion of convertible preferred stock (shares) | | | | 3,263,659 | 10,835,278 | | | |
Conversion of convertible preferred stock | 693,158 | | | $ 3 | $ 11 | 693,144 | | |
Exercise of stock options (shares) | | | | | 3,464 | | | |
Exercise of stock options | 60 | | | | | 60 | | |
Stock-based compensation expense | 10,387 | | | | | 10,387 | | |
Exercise of common stock warrants | 126 | | | | | 126 | | |
Other comprehensive income (loss) | (55) | | | | | | (55) | |
Net loss | (46,384) | | | | | | | (46,384) |
Stockholders (deficit) equity, ending balance (shares) at Jul. 31, 2018 | | | | 3,263,659 | 23,073,611 | | | |
Stockholders (deficit) equity, ending balance at Jul. 31, 2018 | $ 94,498 | | | $ 3 | $ 23 | 943,722 | 414 | (849,664) |
Increase (Decrease) in Convertible Preferred Stock [Roll Forward] | | | | | | | | |
Conversion of convertible preferred stock (shares) | 0 | | | | | | | |
Conversion of convertible preferred stock | $ 0 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Oct. 31, 2018 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Oct. 31, 2018 | $ 0 | | | | | | | |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Initial public offering costs | 110 | | | | | 110 | | |
Conversion of convertible preferred stock (shares) | | | | 0 | 0 | | | |
Conversion of convertible preferred stock | 0 | | | $ 0 | $ 0 | 0 | | |
Exercise of stock options (shares) | | | | | 578 | | | |
Exercise of stock options | 4 | | | | | 4 | | |
Stock-based compensation expense | 4,850 | | | | | 4,850 | | |
Other comprehensive income (loss) | (58) | | | | | | (58) | |
Net loss | (32,545) | $ (4,033) | $ (28,512) | | | | | (32,545) |
Stockholders (deficit) equity, ending balance (shares) at Oct. 31, 2018 | | | | 3,263,659 | 23,074,189 | | | |
Stockholders (deficit) equity, ending balance at Oct. 31, 2018 | $ 66,859 | | | $ 3 | $ 23 | 948,686 | 356 | (882,209) |
Convertible preferred stock, beginning balance (shares) at Jan. 31, 2019 | 0 | | | | | | | |
Convertible preferred stock, beginning balance at Jan. 31, 2019 | $ 0 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Apr. 30, 2019 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Apr. 30, 2019 | $ 0 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Jan. 31, 2019 | | 3,263,659 | 23,434,542 | 3,263,659 | 23,434,542 | | | |
Stockholders (deficit) equity, beginning balance at Jan. 31, 2019 | 44,527 | | | $ 3 | $ 23 | 956,145 | 438 | (912,082) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Vesting of restricted stock units (shares) | | | | | 357,565 | | | |
Vesting of restricted stock units | 0 | | | | | | | |
Shares repurchased for tax withholdings on vesting of restricted stock (shares) | | | | | (20,726) | | | |
Shares repurchased for tax withholdings on vesting of restricted stock | (900) | | | | | (900) | | |
Issuance of common stock under employee stock purchase plan (shares) | | | | | 253,104 | | | |
Issuance of common stock under employee stock purchase plan | 4,519 | | | | $ 1 | 4,518 | | |
Exercise of stock options (shares) | | | | | 61,844 | | | |
Exercise of stock options | 1,338 | | | | | 1,338 | | |
Stock-based compensation expense | 7,653 | | | | | 7,653 | | |
Exercise of common stock warrants (shares) | | | | | 3,130 | | | |
Exercise of common stock warrants | 0 | | | | | 0 | | |
Other comprehensive income (loss) | (56) | | | | | | (56) | |
Net loss | (35,536) | | | | | | | (35,536) |
Stockholders (deficit) equity, ending balance (shares) at Apr. 30, 2019 | | | | 3,263,659 | 24,089,459 | | | |
Stockholders (deficit) equity, ending balance at Apr. 30, 2019 | $ 21,545 | | | $ 3 | $ 24 | 968,754 | 382 | (947,618) |
Convertible preferred stock, beginning balance (shares) at Jan. 31, 2019 | 0 | | | | | | | |
Convertible preferred stock, beginning balance at Jan. 31, 2019 | $ 0 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Oct. 31, 2019 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Oct. 31, 2019 | $ 0 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Jan. 31, 2019 | | 3,263,659 | 23,434,542 | 3,263,659 | 23,434,542 | | | |
Stockholders (deficit) equity, beginning balance at Jan. 31, 2019 | $ 44,527 | | | $ 3 | $ 23 | 956,145 | 438 | (912,082) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Exercise of stock options (shares) | 76,164 | | | | | | | |
Exercise of common stock warrants (shares) | | | | | 3,130 | | | |
Net loss | $ (95,797) | $ (11,435) | $ (84,362) | | | | | |
Stockholders (deficit) equity, ending balance (shares) at Oct. 31, 2019 | | 3,263,659 | 24,602,208 | 3,263,659 | 24,602,208 | | | |
Stockholders (deficit) equity, ending balance at Oct. 31, 2019 | $ (25,181) | | | $ 3 | $ 25 | 982,239 | 431 | (1,007,879) |
Convertible preferred stock, beginning balance (shares) at Apr. 30, 2019 | 0 | | | | | | | |
Convertible preferred stock, beginning balance at Apr. 30, 2019 | $ 0 | | | | | | | |
Convertible preferred stock, ending balance (shares) at Jul. 31, 2019 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Jul. 31, 2019 | $ 0 | | | | | | | |
Stockholders (deficit) equity, beginning balance (shares) at Apr. 30, 2019 | | | | 3,263,659 | 24,089,459 | | | |
Stockholders (deficit) equity, beginning balance at Apr. 30, 2019 | 21,545 | | | $ 3 | $ 24 | 968,754 | 382 | (947,618) |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Vesting of restricted stock units (shares) | | | | | 143,893 | | | |
Vesting of restricted stock units | 0 | | | | | | | |
Shares repurchased for tax withholdings on vesting of restricted stock (shares) | | | | | (3,677) | | | |
Shares repurchased for tax withholdings on vesting of restricted stock | (112) | | | | | (112) | | |
Exercise of stock options (shares) | | | | | 4,928 | | | |
Exercise of stock options | 93 | | | | | 93 | | |
Stock-based compensation expense | 4,738 | | | | | 4,738 | | |
Other comprehensive income (loss) | (10) | | | | | | (10) | |
Net loss | (31,160) | | | | | | | (31,160) |
Stockholders (deficit) equity, ending balance (shares) at Jul. 31, 2019 | | | | 3,263,659 | 24,234,603 | | | |
Stockholders (deficit) equity, ending balance at Jul. 31, 2019 | $ (4,906) | | | $ 3 | $ 24 | 973,473 | 372 | (978,778) |
Convertible preferred stock, ending balance (shares) at Oct. 31, 2019 | 0 | | | | | | | |
Convertible preferred stock, ending balance at Oct. 31, 2019 | $ 0 | | | | | | | |
Increase (Decrease) in Stockholders' Equity (Deficit) [Roll Forward] | | | | | | | | |
Vesting of restricted stock units (shares) | | | | | 110,561 | | | |
Vesting of restricted stock units | 0 | | | | | | | |
Shares repurchased for tax withholdings on vesting of restricted stock (shares) | | | | | (5,522) | | | |
Shares repurchased for tax withholdings on vesting of restricted stock | (98) | | | | | (98) | | |
Issuance of common stock under employee stock purchase plan (shares) | | | | | 253,174 | | | |
Issuance of common stock under employee stock purchase plan | 3,294 | | | | $ 1 | 3,293 | | |
Exercise of stock options (shares) | | | | | 9,392 | | | |
Exercise of stock options | 70 | | | | | 70 | | |
Stock-based compensation expense | 5,501 | | | | | 5,501 | | |
Other comprehensive income (loss) | 59 | | | | | | 59 | |
Net loss | (29,101) | $ (3,437) | $ (25,664) | | | | | (29,101) |
Stockholders (deficit) equity, ending balance (shares) at Oct. 31, 2019 | | 3,263,659 | 24,602,208 | 3,263,659 | 24,602,208 | | | |
Stockholders (deficit) equity, ending balance at Oct. 31, 2019 | $ (25,181) | | | $ 3 | $ 25 | $ 982,239 | $ 431 | $ (1,007,879) |