Income Taxes - Reconciliation of Statutory Federal Income Tax Rate to Effective Income Tax Rate (Detail)	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Federal rate (percent)	35.00%	35.00%	[1]
State and local income taxes, net of federal income tax benefit (percent)	2.20%	3.00%	[1]
Tax-exempt income (percent)	(2.50%)	(2.80%)	[1]
Foreign operations (percent)	(1.90%)	(4.40%)	[1]
Tax credits (percent)	(0.80%)	(2.20%)	[1]
Tax litigation (percent)	0.00%	19.40%	[1]
Leverage lease adjustment (percent)	(1.00%)	(2.30%)	[1]
Other – net (percent)	(1.40%)	0.90%	[1]
Effective tax rate (percent)	29.60%	46.60%	[1]

[1] Results for the first nine months of 2013 were restated to reflect the retrospective application of adopting new accounting guidance in the first quarter of 2014 related to our investments in qualified affordable housing projects (ASU 2014-01). See Note 2 of the Notes to Consolidated Financial Statements for additional information.