Other Revenues and Restructuring Charges - Additional Information (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
Dec. 31, 2015 |
|
| Restructuring Cost and Reserve [Line Items] | |||||
| Revenues | $ 104,621,000 | $ 126,401,000 | $ 409,192,000 | $ 345,207,000 | |
| Amortization of in-process revenue contracts | 0 | 1,200,000 | 0 | ||
| Restructuring charges | 0 | $ 327,000 | 0 | 4,772,000 | |
| Restructuring charges | 4,700,000 | ||||
| Restructuring liability | 0 | 0 | $ 0 | ||
| Amount of restructuring receivables recoverable from customer | 0 | 0 | $ 0 | ||
| Lightering Support Operations [Member] | |||||
| Restructuring Cost and Reserve [Line Items] | |||||
| Revenues | $ 9,000,000 | $ 28,900,000 | |||
| Contract Termination [Member] | |||||
| Restructuring Cost and Reserve [Line Items] | |||||
| Restructuring charges | $ 4,400,000 | ||||