Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Aug. 17, 2010
Long-term debt
Total debt	$ 935,182	$ 988,125
Senior Notes, Noncurrent			325,000
Less: current portion of long-term debt	(25,000)	(14,903)
Total long-term debt	910,182	973,222
Senior Subordinated Notes [Member]
Long-term debt
Senior Notes, Noncurrent	325,000	325,000
Term Loan A [Member] | Credit Agreement [Member]
Long-term debt
Total debt	143,750	158,653
Term Loan B [Member] | Credit Agreement [Member]
Long-term debt
Total debt	$ 466,432	$ 504,472