Income Taxes - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Accrued interest and penalties related to uncertain tax positions	$ 0	$ 0	$ 0
Operating loss carry-forwards	8,700,000	$ 8,300,000	$ 8,700,000	$ 37,300,000
U.S. statutory rate		21.00%	21.00%	34.00%
Tax reform, additional income tax benefit	100,000
Tax reform, additional tax expense	5,900,000
Tax reform, reduction of valuation allowance	5,900,000
Deferred tax assets, operating loss carry-forwards	10,793,000	$ 12,758,000	$ 10,793,000	$ 8,610,000
Deferred tax assets, operating loss carryforwards, portion available after application of IRC Section 382 limitations		54,500,000
Operating loss, subject to expiration		37,300,000
Net deferred tax liabilities	$ 0	0	0
Benefit from income taxes		(10,000)	$ (11,000)	$ 115,000
U.S. Federal
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carry-forwards		108,800,000
State and Local
Operating Loss Carryforwards [Line Items]
Deferred tax assets, operating loss carry-forwards		$ 64,500,000