Revolving Credit Facility and Long-Term Debt - Principal Balances under Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Line of Credit Facility [Line Items]
Total long-term debt	$ 248,854	$ 237,566
Less current portion	10,000	10,000
Long-term portion	238,854	227,566
Term Loan
Line of Credit Facility [Line Items]
Total long-term debt	92,500	100,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Total long-term debt	$ 156,354	$ 137,566