Stockholders' Equity - Summary of Items in Consolidated Income Statements Affected by Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Comprehensive Income Loss Amount Reclassified From Accumulated Other Comprehensive Income [Abstract]
Gains and losses on sale of AFS securities
Tax effect
Net of tax
Amortization of unrealized net gain (loss) on securities transferred to held-to-maturity	665	(2,984)
Tax effect	225	(1,078)
Net of tax	440	(1,906)
Amortization of defined benefit pension and post-retirement items	53	1,754
Tax effect	19	657
Net of tax	34	1,097
Gains and losses on cash flow hedges		171
Tax effect		67
Net of tax		104
Total reclassifications, net of tax	$ 474	$ (705)