Investment Securities (Amortized Cost And Estimated Fair Value Of Investment Securities Available For Sale) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 355,160	$ 330,060	$ 328,766
Gross Unrealized Gains	12,606	10,551	8,374
Gross Unrealized Losses	(786)	(644)	(2,764)
Fair Value	366,980	339,967	334,376
U.S. government agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	8,602	14,670	24,056
Gross Unrealized Gains	296	267	203
Fair Value	8,898	14,937	24,259
State, county and municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	95,354	75,665	58,636
Gross Unrealized Gains	5,047	3,558	1,950
Gross Unrealized Losses	(74)	(90)	(40)
Fair Value	100,327	79,133	60,546
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,792	11,640	11,637
Gross Unrealized Gains	231	167	242
Gross Unrealized Losses	(517)	(406)	(2,157)
Fair Value	11,506	11,401	9,722
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	239,412	228,085	234,437
Gross Unrealized Gains	7,032	6,559	5,979
Gross Unrealized Losses	(195)	(148)	(567)
Fair Value	$ 246,249	$ 234,496	$ 239,849

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details