Commitments and Contingencies - Future Minimum Payments and Maturities of Leases (Details) $ in Thousands	Apr. 30, 2018 USD ($)
Future maturities of capital lease obligations
2019	$ 7,289
2020	5,665
2021	3,882
2022	1,937
2023	1,147
Thereafter	571
Total	20,491
Less: Interest	1,927
Capitalized lease obligations	18,564
Future minimum lease payments under noncancelable operating leases
2018	59,529
2019	52,815
2020	43,120
2021	29,299
2022	17,820
Thereafter	13,601
Total	$ 216,184