Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Long-term debt
Total debt	$ 1,169,757	$ 935,182
Less: current portion of long-term debt	(45,325)	(25,000)
Total long-term debt	1,124,432	910,182
Senior Subordinated Notes [Member]
Long-term debt
Senior Notes, Noncurrent	325,000	325,000
Revolving Credit Facility [Member]
Long-term debt
Line of Credit Facility, Amount Outstanding	27,000	0
Term Loan A, Dated August 17, 2010 [Member] | Loans Payable [Member]
Long-term debt
Total debt	0	143,750
Term Loan B, Dated August 17, 2010 [Member] | Loans Payable [Member]
Long-term debt
Total debt	0	466,432
Term Loan B, dated October 18, 2013 [Member] | Loans Payable [Member]
Long-term debt
Total debt	663,492	0
Term Loan C, Dated October 18, 2013 [Member] | Loans Payable [Member]
Long-term debt
Total debt	$ 154,265	$ 0