Long-Term Debt - Components of Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Components of Long-term debt
Long-term debt	$ 188,150		$ 196,100
Current portion of long-term debt	27,200		15,900
Long-term debt (less current portion)	160,950		180,200
Fair value of long-term debt	194,000	[1]	196,100	[1]
Variable rate credit facilities
Components of Long-term debt
Long-term debt	0		0
Term loan
Components of Long-term debt
Long-term debt	$ 188,150		$ 196,100

[1] * Fair value was estimated based on current rates available to the Company for debt of the same remaining maturity and are classified as Level 2 in the fair value hierarchy.