Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands |
3 Months Ended |
Apr. 30, 2019 |
Apr. 30, 2018 |
| Income Taxes [Line Items] |
|
|
| Provision for income taxes |
$ 1,266
|
$ 848
|
| Unrecognized tax benefits |
$ 37,900
|
|
| U.S. federal tax authorities [Member] | Earliest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2013
|
|
| U.S. federal tax authorities [Member] | Latest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2018
|
|
| U.S. state tax authorities [Member] | Earliest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2009
|
|
| U.S. state tax authorities [Member] | Latest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2018
|
|
| Foreign tax authorities [Member] | Earliest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2013
|
|
| Foreign tax authorities [Member] | Latest tax year [Member] |
|
|
| Income Taxes [Line Items] |
|
|
| Income tax examination, year |
2018
|
|