Long-term Debt and Derivatives (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2011	Dec. 31, 2010
Long-term Debt
Debt	$ 1,969,583	$ 2,171,123
Less current maturities of long-term debt	(45,581)	(357,927)
Long-term debt, net of current maturities	1,922,192	1,813,196
Senior secured credit facility due October 2012
Long-term Debt
Debt	1,639,375	1,589,125
Less discount on senior secured credit facility term loan B	(1,810)
$250 million 6 3/4% senior subordinated notes due March 2015
Long-term Debt
Debt		250,000
Debt instrument interest rate stated percentage (as a percent)	6.75%	6.75%
$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 (as a percent)	8.75%	8.75%
Other long-term obligations
Long-term Debt
Debt	1,919	3,782
Capital leases
Long-term Debt
Debt	$ 3,289	$ 3,216