XML 34 R46.htm IDEA: XBRL DOCUMENT v2.4.0.6
Basis of presentation and Significant Accounting Policies (Details Textual) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Basis Of Presentation (Textual) [Abstract]      
Depreciation of vessels and equipment $ 73.2 $ 72.8 $ 69.0
Interest cost capitalized to vessels and equipment $ 3.1 $ 4.2 $ 10.8
Tax rate in Spain 30.00%    
Effective income tax rate on revenue by Spanish vessels tax credit 90.00%    
Effective tax rate on revenues by Spanish vessels 3.00%    
Interest costs capitalized to vessels and equipment 3.1 4.2 10.8
Conventional Tankers [Member]
      
Property, Plant and Equipment [Line Items]      
Estimated useful life in years 25    
LPG Carriers [Member]
      
Property, Plant and Equipment [Line Items]      
Estimated useful life in years 30    
LNG Carriers [Member]
      
Property, Plant and Equipment [Line Items]      
Estimated useful life in years 35