Debt Senior Credit Facility (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 Term Loan A	Jun. 30, 2013 Term Loan A2	Jun. 30, 2013 Term Loan B	Apr. 03, 2013 Term Loan B	Jun. 30, 2013 Revolver	Apr. 03, 2013 Revolver	Jun. 30, 2013 Letter of Credit	Jun. 30, 2013 Additional Revolver	Apr. 03, 2013 London Interbank Offered Rate (LIBOR) [Member] Term Loan B
Line of Credit Facility [Line Items]
Face amount						$ 300,000,000
Basis spread on variable rate			2.75%	2.75%	2.75%		2.75%				2.50%
Floor interest rate											0.75%
Current borrowing capacity								700,000,000
Debt Issuance Cost	10,200,000
Payments of Debt Extinguishment Costs	1,100,000
Payments of Financing Costs	9,100,000
Write off unamortized debt discount	1,100,000
Write off of Deferred Debt Issuance Cost	3,300,000
Line of Credit Facility, Remaining Borrowing Capacity	295,000,000
Long-term Debt					300,000,000				58,200,000	346,800,000
Revolver	$ 295,000,000	$ 235,000,000
Long-term Debt, Weighted Average Interest Rate	3.00%
Total Leverage Ratio	5.75
Senior Secured Leverage Ratio	3.50
Interest Coverage Ratio	3.00