Summary of Debt Outstanding Based On Stated Maturities (Parenthetical) (Detail) |
12 Months Ended |
---|---|
Dec. 31, 2018 | |
8.00% Secured Notes Due August 2022 | |
Debt [Line Items] | |
Debt instrument interest rate | 8.00% |
Debt Instrument Maturity Period | August 2022 |
Norwegian Kroner Denominated Notes Due May 2024 | Troms Offshore Supply AS | |
Debt [Line Items] | |
Debt Instrument Maturity Period | May 2024 |
Norwegian Kroner Denominated Notes Due January 2026 | Troms Offshore Supply AS | |
Debt [Line Items] | |
Debt Instrument Maturity Period | January 2026 |
United States Dollar Denominated Notes Due January 2027 | Troms Offshore Supply AS | |
Debt [Line Items] | |
Debt Instrument Maturity Period | January 2027 |
United States Dollar Denominated Notes Due April 2027 | Troms Offshore Supply AS | |
Debt [Line Items] | |
Debt Instrument Maturity Period | April 2027 |