Income Taxes - Tax Reconciliation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Income Tax Rate Reconciliation [Line Items]
Document Fiscal Year Focus	2017
Computed expected tax expense (benefit)	$ 1,190,000	$ 933,000	$ 1,730,000
State income tax, net of federal benefit	108,000	56,000	224,000
Valuation allowance	(1,512,000)	(1,239,000)	(3,556,000)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	(9,737,000)	0	0
All other items	304,000	97,000	(2,000)
Federal Income Tax Expense (Benefit), Continuing Operations	$ (9,647,000)	$ (153,000)	$ (1,604,000)