Income Taxes - Details of Reconciliation of Income Taxes (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	35.00%	35.00%
Increase (decrease) in taxes resulting from:
State and local taxes	(7.80%)	17.30%	2.00%
Nondeductible items	(2.90%)	(17.60%)	0.80%
Tax Cuts and Jobs Act of 2017		(147.70%)
Prior year true-up items	6.90%	6.80%
Refundable Tax Credits	1.50%	3.60%
Other, net	(0.10%)	0.10%	(0.10%)
Change in valuation allowance		(0.10%)	(2.40%)
Effective income tax rate	18.60%	(102.60%)	35.30%