v3.5.0.2
Segment Reporting - Reconciliation of Total Segment Assets to Total Assets Presented in Consolidated Balance Sheets (Detail) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Sep. 30, 2015
Dec. 31, 2014
Segment Reporting, Asset Reconciling Item [Line Items]        
Cash and cash equivalents $ 59,237 $ 96,417 $ 80,579 $ 162,797
Accounts receivable 25,245 28,313    
Consolidated total assets 1,957,784 2,169,476    
Conventional Tankers [Member]        
Segment Reporting, Asset Reconciling Item [Line Items]        
Consolidated total assets 1,842,803 2,020,317    
Ship-to-Ship Transfer [Member]        
Segment Reporting, Asset Reconciling Item [Line Items]        
Consolidated total assets $ 30,499 $ 24,429