Senior Debt (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Covenants [Abstract]
Covenant limitation incur additional debt in excess of	$ 250,000,000
Maximum pro forma senior leverage ratio	2.50
Consolidated funded debt outstanding	659,500,000
Consolidated EBITDA	387,100,000
Outstanding indebtedness less cash in excess of	25,000,000
Adjusted Consolidated EBITDA	514,600,000
Consolidated fixed charges	325,100,000
Debt Instrument [Line Items]
Senior credit facilities, maximum facility	750,000,000	1,024,080,000
Senior credit facilities, amount outstanding	422,500,000	383,334,000
Senior credit facilities, amount available	198,805,000	231,629,000
Debt facilities, maximum facility	770,000,000	1,044,080,000
Debt facilities, amount outstanding	440,675,000	401,114,000
Debt facilities, amount available	200,630,000	233,849,000
Letters of credit, outstanding	116,200,000	137,400,000
Financial Covenants Ratios (Table Details) [Abstract]
Required consolidated leverage ratio, maximum	3.25
Actual consolidated leverage ratio	1.70
Required fixed charge coverage ratio, minimum	1.35
Actual fixed charge coverage ratio	1.58
Interest Rate [Abstract]
Interest accrued at prime rate plus %, minimum	0.50%
Interest accrued at prime rate plus %, maximum	1.50%
Interest accrued at Eurodollar rate plus %, minimum	1.50%
Interest accrued at Eurodollar rate plus %, maximum	2.50%
Commitment fee percentage, minimum	0.30%
Commitment fee percentage, maximum	0.50%
Schedule Maturity Dates (Table Details) [Abstract]
2012	43,175,000
2013	25,000,000
2014	25,000,000
2015	25,000,000
2016	322,500,000
Senior debt	440,675,000	401,114,000
Senior Debt (Details) [Abstract]
Proceeds from term loan	250,000,000
Revolving credit facility drawn amount	100,000,000
Event of default-3rd party ownership % of our voting stock	35.00%
Event of default-not satisfied or bonded judgment in excess of	50,000,000
Maximum period allowed for pending judgment to satisfy or bond (in days)	30
Maximum fund drawn on individual occasion	100,000,000
Maximum total amount outstanding	186,500,000
Term Loan Existing Atranche [Member]
Debt Instrument [Line Items]
Maturity date	Jun. 30, 2011
Term loan, maximum facility		82,500,000
Term loan, amount outstanding		18,750,000
Term Loan Extended Atranche [Member]
Debt Instrument [Line Items]
Maturity date	Sep. 30, 2013
Term loan, maximum facility		82,500,000
Term loan, amount outstanding		55,000,000
Term Loan Existing Btranche [Member]
Debt Instrument [Line Items]
Maturity date	Jun. 30, 2012
Term loan, maximum facility		184,080,000
Term loan, amount outstanding		13,334,000
Term Loan Extended Btranche [Member]
Debt Instrument [Line Items]
Maturity date	Mar. 31, 2015
Term loan, maximum facility		300,000,000
Term loan, amount outstanding		290,250,000
Intrust Bank Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit, maximum facility	20,000,000	20,000,000
Line of credit, amount outstanding	18,175,000	17,780,000
Line of credit, amount available	1,825,000	2,220,000
Credit Facility Revolver [Member]
Debt Instrument [Line Items]
Maturity date	Jul. 14, 2016
Line of credit, maximum facility	500,000,000	375,000,000
Line of credit, amount outstanding	185,000,000	6,000,000
Line of credit, amount available	198,805,000	231,629,000
Credit Facility New Term Loan [Member]
Debt Instrument [Line Items]
Maturity date	Jul. 14, 2016
Term loan, maximum facility	250,000,000
Term loan, amount outstanding	$ 237,500,000