Restricted Cash - Additional Information (Details) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Apr. 30, 2018 |
Oct. 31, 2017 |
|
| Restricted Cash and Cash Equivalents Items [Line Items] | ||
| Restricted cash and cash equivalents | $ 38,200 | $ 38,200 |
| Restricted cash and cash equivalents - long-term | 32,965 | 33,526 |
| Reserves for obligations | $ 17,200 | 17,000 |
| Letter of credit date of expiration | Apr. 30, 2019 | |
| Letters of credit outstanding, amount | $ 2,300 | 2,900 |
| Dominion Bridgeport FuelCell Park [Member] | ||
| Restricted Cash and Cash Equivalents Items [Line Items] | ||
| Restricted cash and cash equivalents - long-term | $ 15,000 | $ 15,000 |
| Restricted cash and cash equivalents - long-term service agreement | 15 years |