Long-term Debt and Derivatives (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Long-term Debt
Debt	$ 2,103,661	$ 2,044,914
Less current maturities of long-term debt	(42,600)	(44,559)
Less discount on senior secured credit facility term loan B	(1,628)	(1,749)
Long-term debt, net of current maturities	2,059,433	1,998,606
Senior secured credit facility
Long-term Debt
Debt	1,776,500	1,715,750
$325 million 8 3/4% senior subordinated notes due August 2019
Long-term Debt
Debt	325,000	325,000
Debt instrument interest rate stated percentage	8.75%
Other long-term obligations
Long-term Debt
Debt		1,949
Capital leases
Long-term Debt
Debt	$ 2,161	$ 2,215