Leases - Lease Maturities (Details) - USD ($)
$ in Thousands
Apr. 30, 2019
Jan. 31, 2019
Finance Lease Liabilities, Payments, Due [Abstract]    
Remainder of 2020 $ 3,732  
2021 8,073  
2022 8,073  
2023 8,073  
2024 8,073  
Thereafter 51,274  
Total minimum payments 87,298  
Less imputed interest (22,410)  
Present value of future minimum lease payments 64,888  
Less current obligations under leases (2,133)  
Non-current lease obligations 62,755  
Operating Lease Liabilities, Payments Due [Abstract]    
Remainder of 2020 4,017  
2021 4,189  
2022 2,579  
2023 2,529  
2024 1,014  
Thereafter 2,103  
Total minimum payments 16,431  
Less imputed interest (3,029)  
Present value of future minimum lease payments 13,402  
Less current obligations under leases (3,575) $ 0
Non-current lease obligations $ 9,827 $ 0