Restructuring Charges - Accrued Liability Rollforward (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Jul. 31, 2017 |
Jul. 31, 2016 |
|
| Restructuring Cost and Reserve [Line Items] | ||
| Balance at April 30, 2016 | $ 1,407 | $ 1,043 |
| Restructuring charges | 40 | 327 |
| Payments | (1,161) | (470) |
| Non-cash settlements of restructuring charges | (24) | |
| Balance at July 31, 2017 | 262 | 900 |
| Employee Severance [Member] | ||
| Restructuring Cost and Reserve [Line Items] | ||
| Balance at April 30, 2016 | 1,108 | 497 |
| Restructuring charges | 40 | 327 |
| Payments | (1,148) | (341) |
| Non-cash settlements of restructuring charges | 0 | |
| Balance at July 31, 2017 | 0 | 483 |
| Other Restructuring [Member] | ||
| Restructuring Cost and Reserve [Line Items] | ||
| Balance at April 30, 2016 | 299 | 546 |
| Restructuring charges | 0 | 0 |
| Payments | (13) | (129) |
| Non-cash settlements of restructuring charges | (24) | |
| Balance at July 31, 2017 | $ 262 | $ 417 |