Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Effective income tax rate	23.00%	38.00%	41.00%
Unrecognized tax benefits	$ 0	$ 0
Earliest Tax Year [Member]
Income Tax [Line Items]
Year of income tax returns open to examination	2007
Latest Tax Year [Member]
Income Tax [Line Items]
Year of income tax returns open to examination	2016
State Income Tax [Member]
Income Tax [Line Items]
Net operating loss carryforwards for state income tax	$ 36,000