Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Remeasurement of deferred tax assets and liabilities, income tax expense	$ 827,000
Unrecognized tax benefits	0	$ 0
Expected increase of unrecognized tax benefits in next 12 months	$ 0