|
Vessel Sales and Impairments - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | 1 Months Ended | |||||
|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Dec. 31, 2012
Impaired Asset [Member]
Suezmax tankers [Member]
Vessel
|
Dec. 31, 2012
Impaired Asset [Member]
Aframax tankers [Member]
Vessel
|
Dec. 31, 2012
Impaired Asset [Member]
Product tankers [Member]
Vessel
|
Dec. 31, 2011
Impaired Asset [Member]
Product tankers [Member]
Vessel
|
Dec. 31, 2012
Assets Held-for-sale [Member]
Aframax tankers [Member]
Vessel
|
Jan. 31, 2013
Sold Asset [Member]
Aframax tankers [Member]
Vessel
|
|
| Impaired Long-Lived Assets Held and Used [Line Items] | |||||||
| Vessel impairment and net loss on sale of vessels | $ 352.5 | $ 305.6 | $ 44.5 | $ 2.4 | $ 58.0 | ||
| Number of vessels | 7 | 4 | 1 | 3 | 1 | 1 | |