Fair Value Measurements - Additional Information about Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 32,565	$ 11,603
Total gains (losses) - realized/unrealized, Included in earnings	78
Total gains (losses) - realized/unrealized, Included in other comprehensive income	6,705	1,802
Accretion included in earnings	3,176	2,544
Purchases		21,753
Issuances	38	46
Sales/redemptions	(1,033)	(2,542)
Settlements	(1,698)	(2,641)
Transfers from Level 3	(6,082)
Transfers into Level 3
Balance at end of period	33,749	32,565
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	22,456	5,998
Total gains (losses) - realized/unrealized, Included in earnings
Total gains (losses) - realized/unrealized, Included in other comprehensive income	6,701	917
Accretion included in earnings	3,160	2,515
Purchases		16,569
Issuances	38	46
Sales/redemptions		(2,542)
Settlements	(760)	(1,047)
Transfers from Level 3
Transfers into Level 3
Balance at end of period	31,595	22,456
Other Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	6,892	5,197
Total gains (losses) - realized/unrealized, Included in earnings	78
Total gains (losses) - realized/unrealized, Included in other comprehensive income	21	732
Accretion included in earnings	4	9
Purchases		954
Issuances
Sales/redemptions	(1,033)
Settlements
Transfers from Level 3	(5,962)
Transfers into Level 3
Balance at end of period		6,892
Equity securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	512	408
Total gains (losses) - realized/unrealized, Included in earnings
Total gains (losses) - realized/unrealized, Included in other comprehensive income	18	104
Accretion included in earnings
Purchases
Issuances
Sales/redemptions
Settlements
Transfers from Level 3	(120)
Transfers into Level 3
Balance at end of period	410	512
Residential Non-Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	2,705
Total gains (losses) - realized/unrealized, Included in earnings
Total gains (losses) - realized/unrealized, Included in other comprehensive income	(35)	49
Accretion included in earnings	12	20
Purchases		4,230
Issuances
Sales/redemptions
Settlements	(938)	(1,594)
Transfers from Level 3
Transfers into Level 3
Balance at end of period	$ 1,744	$ 2,705