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Change in Accounting Estimate - Additional Information (Detail) (USD $)
In Millions, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2013
Shuttle tankers [Member]
Vessel
Dec. 31, 2013
Service Life [Member]
Shuttle tankers [Member]
Vessel
Dec. 31, 2013
Original useful life [Member]
Older shuttle tankers [Member]
Dec. 31, 2013
Reduced useful life [Member]
Older shuttle tankers [Member]
Change in Accounting Estimate [Line Items]          
Estimated useful life       25 years 20 years
Number of vessels   6 6    
Increase in depreciation and amortization expenses $ 14.9        
Decrease in net income attributable to partners $ 4.4        
Decrease in net income attributable to partners, per share amount $ 0.06