Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Examination [Line Items]
Income tax provision	$ 297,000	$ (116,000)	$ 444,000	$ 10,000
Effective income tax rate (as a percent)			21.00%	1.00%
U.S. statutory tax rate (as a percent)				34.00%
Excess tax benefit from the exercise of stock options	$ 37,000		$ 70,000	$ 207,000
Need for valuation allowance based on history of cumulative losses			3 years