Securities - Estimated Fair Value and Unrealized Loss for Securities Held-to-Maturity (Detail) (Held-to-Maturity Securities [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	$ 207,999	$ 246,105
Held-to-maturity, Less than 12 months, Unrealized Losses	(4,155)	(8,334)
Held-to-maturity, 12 months or longer, Estimated Fair Value	82,995	45,403
Held-to-maturity, 12 months or longer, Unrealized Losses	(11,650)	(10,754)
Held-to-maturity, Total, Estimated Fair Value	290,994	291,508
Held-to-maturity, Total, Unrealized Losses	(15,805)	(19,088)
U.S. Agency Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	40,654
Held-to-maturity, Less than 12 months, Unrealized Losses	(158)
Held-to-maturity, 12 months or longer, Estimated Fair Value
Held-to-maturity, 12 months or longer, Unrealized Losses
Held-to-maturity, Total, Estimated Fair Value	40,654
Held-to-maturity, Total, Unrealized Losses	(158)
Investment Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	46,624	39,273
Held-to-maturity, Less than 12 months, Unrealized Losses	(180)	(175)
Held-to-maturity, 12 months or longer, Estimated Fair Value	45,423	45,403
Held-to-maturity, 12 months or longer, Unrealized Losses	(10,038)	(10,754)
Held-to-maturity, Total, Estimated Fair Value	92,047	84,676
Held-to-maturity, Total, Unrealized Losses	(10,218)	(10,929)
Investment Securities [Member] | State And Municipal Obligation [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	5,970	35,747
Held-to-maturity, Less than 12 months, Unrealized Losses	(22)	(144)
Held-to-maturity, 12 months or longer, Estimated Fair Value	460
Held-to-maturity, 12 months or longer, Unrealized Losses	(1)
Held-to-maturity, Total, Estimated Fair Value	6,430	35,747
Held-to-maturity, Total, Unrealized Losses	(23)	(144)
Investment Securities [Member] | Corporate Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value		3,526
Held-to-maturity, Less than 12 months, Unrealized Losses		(31)
Held-to-maturity, 12 months or longer, Estimated Fair Value	44,963	1,153
Held-to-maturity, 12 months or longer, Unrealized Losses	(10,037)	(4)
Held-to-maturity, Total, Estimated Fair Value	44,963	4,679
Held-to-maturity, Total, Unrealized Losses	(10,037)	(10,750)
Investment Securities [Member] | Equity Investments [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value
Held-to-maturity, Less than 12 months, Unrealized Losses
Held-to-maturity, 12 months or longer, Estimated Fair Value		44,250
Held-to-maturity, 12 months or longer, Unrealized Losses		(10,750)
Held-to-maturity, Total, Estimated Fair Value		44,250
Held-to-maturity, Total, Unrealized Losses		(10,750)
Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	161,375	206,832
Held-to-maturity, Less than 12 months, Unrealized Losses	(3,975)	(8,159)
Held-to-maturity, 12 months or longer, Estimated Fair Value	37,572
Held-to-maturity, 12 months or longer, Unrealized Losses	(1,612)
Held-to-maturity, Total, Estimated Fair Value	198,947	206,832
Held-to-maturity, Total, Unrealized Losses	(5,587)	(8,159)
Mortgage-Backed Securities [Member] | FHLMC [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	101,331	122,365
Held-to-maturity, Less than 12 months, Unrealized Losses	(2,100)	(4,552)
Held-to-maturity, 12 months or longer, Estimated Fair Value	21,295
Held-to-maturity, 12 months or longer, Unrealized Losses	(890)
Held-to-maturity, Total, Estimated Fair Value	122,626	122,365
Held-to-maturity, Total, Unrealized Losses	(2,990)	(4,552)
Mortgage-Backed Securities [Member] | FNMA [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity, Less than 12 months, Estimated Fair Value	60,044	84,467
Held-to-maturity, Less than 12 months, Unrealized Losses	(1,875)	(3,607)
Held-to-maturity, 12 months or longer, Estimated Fair Value	16,277
Held-to-maturity, 12 months or longer, Unrealized Losses	(722)
Held-to-maturity, Total, Estimated Fair Value	76,321	84,467
Held-to-maturity, Total, Unrealized Losses	$ (2,597)	$ (3,607)