v2.4.0.6
Fair value of financial instruments (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2012
Dec. 31, 2011
Fair value of financial instruments    
Restricted cash $ 28,618 $ 21,412
Derivative assets current 9,456 10,411
Derivative assets non-current 11,115 22,003
Derivative liabilities current 33,038 20,592
Derivative liabilities non-current 118,070 33,170
Carrying Amount
   
Fair value of financial instruments    
Cash and cash equivalents 60,191 60,651
Restricted cash 28,618 21,412
Derivative assets current 9,456 10,411
Derivative assets non-current 11,115 22,003
Derivative liabilities current 33,038 20,592
Derivative liabilities non-current 118,070 33,170
Revolving credit facility and long-term debt, including current portion 1,647,341 1,483,858
Convertible debentures 424,246 189,563
Fair Value
   
Fair value of financial instruments    
Cash and cash equivalents 60,191 60,651
Restricted cash 28,618 21,412
Derivative assets current 9,456 10,411
Derivative assets non-current 11,115 22,003
Derivative liabilities current 33,038 20,592
Derivative liabilities non-current 118,070 33,170
Revolving credit facility and long-term debt, including current portion 1,701,811 1,462,474
Convertible debentures $ 416,677 $ 207,888