Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Components of Long-term Debt
Total long-term debt	$ 386,755	$ 346,047
8.625% Senior Notes [Member]
Components of Long-term Debt
Total long-term debt	300,000	300,000
Revolving Credit Facility [Member]
Components of Long-term Debt
Total long-term debt	$ 86,755	$ 46,047