Revolving Credit Facility and Long-Term Debt - Principal Balances under Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Feb. 23, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Total long-term debt	$ 237,406		$ 324,373
2017 Debt facility	6,998	$ 7,000	0
Less debt issuance costs	(592)		(627)
Less current portion	16,998		10,000
Long-term portion	220,408		314,373
Term Loan
Line of Credit Facility [Line Items]
Total long-term debt	92,500		145,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Total long-term debt	$ 138,500		$ 180,000