Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Provision (benefit) for federal income taxes at statutory rates	$ (1,672)	$ 711	$ (889)
Provision for state income taxes, net of federal benefit	(479)	421	120
Valuation allowance changes affecting the provision for income taxes	(146)	(372)	(45)
Employment tax credits	(64)	(217)	(529)
Nondeductible expenses	1,919	496	453
Stock based compensation expense	15	(35)	(62)
Effect of Tax Cuts and Jobs Creation Act	0	5,476	0
Other	(323)	263	(78)
Provision (benefit) for income taxes of continuing operations	$ (750)	$ 6,743	$ (1,030)