Sources of Tax Effect (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Statutory Tax Rate	35.00%	35.00%	35.00%
State and local income taxes and other, net of federal income tax benefit	4.80%	(7.10%)	5.80%
Valuation allowance	0.10%	79.10%	1.50%
Tax credits	(0.60%)	136.00%	(8.40%)
Uncertain tax positions	(1.00%)	(230.30%)	0.60%
Other items, net	0.60%	(663.30%)	2.10%
Continuing operations effective income tax rate	38.90%	(650.60%)	36.60%