Income Taxes - Reconciliation of Statutory Federal Income Tax Rate to Effective Income Tax Rate (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Federal rate (percent)	35.00%	35.00%
State and local income taxes, net of federal income tax benefit (percent)	(0.70%)	1.70%
Tax-exempt income (percent)	(2.80%)	(3.00%)
Foreign operations (percent)	(4.60%)	(4.90%)
Tax credits (percent)	(0.80%)	(4.10%)
Tax litigation (percent)	0.00%	103.50%
Other – net (percent)	(1.00%)	0.50%
Effective tax rate (percent)	25.10%	128.70%