Long-Term Debt - Components of Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014		Dec. 31, 2013
Components of Long-term debt
Long-term debt	$ 199,000		$ 200,000
Current portion of long-term debt	2,000		2,000
Long-term debt (less current portion)	197,000		198,000
Fair value of long-term debt	199,000	[1]	200,000
Variable rate credit facility
Components of Long-term debt
Long-term debt	0		0
Term loan
Components of Long-term debt
Long-term debt	$ 199,000		$ 200,000

[1] * Fair value of the term loan was estimated based on quoted private market transactions and is classified as Level 1 in the fair value hierarchy.