Debt (Tables)

12 Months Ended

Dec. 31, 2014

Debt Instrument

Schedule of Long-term Debt Instruments [Table Text Block]

	December 31,
	2014		2013
	(in thousands, except percentages)
Credit facility (1)	$	1,173,175	$	1,173,175
10.25% senior notes due June 2014	—		205,257
6.75% senior notes due November 2020	299,970		300,000
6.375% senior notes due September 2022	599,163		600,000
Net unamortized premiums	14,644		22,729
Total debt, net	2,086,952		2,301,161
Less current maturities	—		(211,558		)
Total long-term debt, net	$	2,086,952	$	2,089,603

⁽¹⁾  Variable interest rate of 2.67% at both December 31, 2014, and December 31, 2013.

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

	December 31, 2014				December 31, 2013
	Carrying Value		Fair Value		Carrying Value		Fair Value
	(in thousands)
Credit facility	$	1,173,175	$	1,173,175	$	1,173,175	$	1,173,175
Senior notes, net	913,777		699,462		1,127,986		1,128,527
Total debt, net	$	2,086,952	$	1,872,637	$	2,301,161	$	2,301,702

6.375% Senior notes due 2022

Debt Instrument

Senior notes, expressed as percentage of principal amount redeemed, plus accured and unpaid interest, by maturity

On and after March 15, 2017, the Company may redeem all or, from time to time, a part of the September 2022 Senior Notes upon not less than 30 nor more than 60 days’ notice, at the following redemption prices (expressed as a percentage of principal amount of notes to be redeemed), plus accrued and unpaid interest, if any, to the applicable redemption date (subject to the right of holders of record on the relevant record date to receive interest due on the relevant interest payment date), if redeemed during the 12-month period beginning on March 15 of the years indicated below:

2017	103.188	%
2018	102.125	%
2019	101.063	%
2020 and thereafter	100.000	%

6.75% Senior notes due 2020

Debt Instrument

Senior notes, expressed as percentage of principal amount redeemed, plus accured and unpaid interest, by maturity

The Company may redeem all or any part of the November 2020 Senior Notes at any time beginning on or after November 1, 2015 at the redemption prices set forth below, expressed as percentages of the principal amount redeemed, plus accrued and unpaid interest:

2015	103.375	%
2016	102.250	%
2017	101.125	%
2018 and thereafter	100.000	%