Annual report pursuant to Section 13 and 15(d)

Financial Instruments (Carrying amounts and fair value of the financial instruments) (Details)

v2.4.0.8
Financial Instruments (Carrying amounts and fair value of the financial instruments) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Carrying Amount [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Current and long-term debt $ 1,047,980 $ 877,051
Fair Value [Member]
   
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Current and long-term debt $ 1,058,431 $ 899,414