Income Taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Examination [Line Items]
Income tax (benefit) expense	$ (62)	$ (85)	$ 287
U.S. TCJA recovery of alternative minimum tax credits	0	73	$ 0
Deferred tax assets valuation allowance	12,120	13,309
Valuation allowance increase (decrease)	(1,200)
Decrease related to changes in deferred taxes	2,000
Valuation allowance, net operating loss	$ 800
Change in ownership percentage (more than)	50.00%
Stockholder ownership (or greater)	5.00%
Not Subject to Limitations
Income Tax Examination [Line Items]
Proceeds from sale of operating loss carryforward	$ 26,500
Subject to Limitations | Minimum
Income Tax Examination [Line Items]
Net operating losses	1,000
Subject to Limitations | Maximum
Income Tax Examination [Line Items]
Net operating losses	$ 2,300
Alternative Minimum Tax Carryover
Income Tax Examination [Line Items]
U.S. TCJA recovery of alternative minimum tax credits		$ 73