Composition of Debt and Capital Lease Obligations (Details) (USD $)	6 Months Ended						6 Months Ended						1 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2012 9% Senior Secured Notes due 2017	Jun. 30, 2012 Senior Notes	Dec. 31, 2011 Senior Notes	Jun. 30, 2012 Senior Notes 9% Senior Secured Notes due 2017	Mar. 06, 2012 Senior Notes 9% Senior Secured Notes due 2017	Dec. 31, 2011 Senior Notes 9% Senior Secured Notes due 2017	Dec. 03, 2010 Senior Notes 9% Senior Secured Notes due 2017	Jun. 30, 2012 Capital Lease Obligations	Dec. 31, 2011 Capital Lease Obligations	Feb. 01, 2011 Senior Subordinated Notes Senior Subordinated Notes due 2014	Dec. 03, 2010 Senior Subordinated Notes Senior Subordinated Notes due 2014	Jun. 30, 2012 Revolving Credit Facility Fourth Amended and Restated Credit Agreement	Dec. 31, 2011 Revolving Credit Facility Fourth Amended and Restated Credit Agreement
Long-term Debt, by Current and Noncurrent [Abstract]
Senior Secured Notes due December 15, 2017, 9% interest payable semi-annually on June 15 and December 15							$ 360,000,000		$ 260,000,000
Senior Secured Notes discount					(4,986,000)	0		(5,200,000)
Capital leases											4,501,000	5,322,000
Long-term obligations	359,515,000		265,322,000
Current maturities	(1,662,000)		(1,715,000)
Long-term obligations, less current maturities	357,853,000		263,607,000
Debt Instruments [Abstract]
Debt Issued								100,000,000		260,000,000
Stated Interest Rate				9.00%				9.00%		9.00%				9.25%
Limitation on Guarantee and Security for Non-Guarantor Foreign Subsidiaries, Voting Stock										65.00%
Limitation on Guarantee and Security for Non-Guarantor Foreign Subsidiaries, Non-Voting Stock										100.00%
Right to Require the Company to Purchase Notes Upon Change in Control							101.00%
Cash Dividends Paid	93,507,000	0					93,500,000
Consent Fee Paid, Per One Million Dollars of Original Principal Amount								20,000
Principal Unit Amount								1,000,000
Extinguishment of Debt Disclosures [Abstract]
Redemption of Debt, Aggregate Value														172,327,000
Redemption of Debt, Percentage of Par														101.542%
Quarterly Special Interest Adjustment													36,000
Interest on Debt, Excluding the Special Interest Adjustment													1,328,000
Amortization of Fair Value Premium to Interest Expense	(214,000)	0											1,110,000
Line of Credit Facility [Abstract]
Letters of Credit Outstanding															1,416,000	1,416,000
Unused Availability, Net of Letters of Credit															58,584,000
Fixed Charge Coverage Ratio Required if Unused Availability is below Threshold															1
Minimum Unused Availability for the Fixed Charge Coverage Ratio to be Not Applicable															$ 9,000,000