Income Taxes - Additional Information (Detail) - USD ($)		3 Months Ended
	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Estimated annual effective tax rate		8.10%
Deferred tax benefit		$ 890,000	$ 858,000
Effective tax rate		50.20%	5.30%
Unrecognized tax benefits		$ 0
Accounting for the 2017 tax cuts and jobs act was complete	false