Debt - Schedule of Outstanding Balances and Maturity Dates for Short Term and Long Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Capital lease obligations, short-term	$ 7	$ 25
Long-term debt and capital leases — current portion	7	25
Long-term debt	115,000	115,000
Capital lease obligations, long-term	6	54
Debt issuance costs	(726)	(737)
Total debt, long-term	114,280	114,317
Notes and Bonds Payable
Debt Instrument [Line Items]
Long-term debt	115,000	115,000
Notes and Bonds Payable | 4.380% Series A 2016, maturing June 2028
Debt Instrument [Line Items]
Long-term debt	28,750	28,750
Notes and Bonds Payable | 4.580% Series B 2016, maturing June 2036
Debt Instrument [Line Items]
Long-term debt	$ 86,250	$ 86,250