Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Long Term Debt And Short Term Debt Instruments [Line Items]
Long-Term Debt	$ 55,000
Less Unamortized Debt Issuance Costs	(288)	$ (561)
Total Long-Term Debt	54,712	54,439
Debt issuance costs	1,000	900
Unsecured Senior Notes
Schedule Of Long Term Debt And Short Term Debt Instruments [Line Items]
Long-Term Debt	55,000	55,000
Wells Fargo Revolving Credit Facility
Schedule Of Long Term Debt And Short Term Debt Instruments [Line Items]
Total Short-Term Debt	$ 54,613	$ 37,055