Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Long-term debt
Total debt	$ 910,182	$ 935,182
Less: current portion of long-term debt	(6,250)	(25,000)
Total long-term debt	903,932	910,182
Senior Subordinated Notes [Member]
Long-term debt
Senior Notes, Noncurrent	325,000	325,000
Term Loan A, maturing August 17, 2015 [Member] | Credit Agreement [Member]
Long-term debt
Total debt	118,750	143,750
Term Loan B, maturing August 17, 2016 [Member] | Credit Agreement [Member]
Long-term debt
Total debt	$ 466,432	$ 466,432