Deferred Contract Costs (Details) - USD ($) |
3 Months Ended | ||
|---|---|---|---|
Apr. 30, 2019 |
Apr. 30, 2018 |
Jan. 31, 2019 |
|
| Revenue from Contract with Customer [Abstract] | |||
| Deferred contract costs | $ 18,600,000 | $ 17,500,000 | |
| Amortization of deferred contract costs | 1,608,000 | $ 833,000 | |
| Impairment loss in relation to costs capitalized | $ 0 | $ 0 | |