XML 18 R28.htm IDEA: XBRL DOCUMENT v3.3.0.814
Fair Value (Details) - USD ($)
$ in Thousands
Sep. 30, 2015
Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value of senior notes $ 542,740 $ 550,000
Amount of difference between fair value and carrying value (43,842) (51,375)
Senior Notes Due 2020 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value of senior notes 292,740 300,000
Amount of difference between fair value and carrying value (6,967) (15,750)
Senior Notes Due 2021 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Carrying value of senior notes 250,000 250,000
Amount of difference between fair value and carrying value (36,875) (35,625)
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of senior notes 498,898 498,625
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member] | Senior Notes Due 2020 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of senior notes 285,773 284,250
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member] | Senior Notes Due 2021 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of senior notes $ 213,125 $ 214,375