Securities (Schedule Of Amortized Cost And Fair Value Of Securities Available For Sale) (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	$ 1,170,439	$ 645,658	$ 744,292
Securities Available For Sale, Gross Unrealized Gains	16,858	9,829	9,856
Securities Available For Sale, Gross Unrealized Loss	(14,614)	(14,916)	(16,023)
Securities Available For Sale, Fair Value	1,172,683	640,571	738,125
U.S. Government-Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	352,910	231,187	299,861
Securities Available For Sale, Gross Unrealized Gains	1,676	642	1,395
Securities Available For Sale, Gross Unrealized Loss	(129)		(688)
Securities Available For Sale, Fair Value	354,457	231,829	300,568
Agency Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	267,575	166,758	205,443
Securities Available For Sale, Gross Unrealized Gains	7,575	4,853	6,064
Securities Available For Sale, Gross Unrealized Loss
Securities Available For Sale, Fair Value	275,150	171,611	211,507
Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	465,574	181,493	146,977
Securities Available For Sale, Gross Unrealized Gains	4,201	2,236	1,081
Securities Available For Sale, Gross Unrealized Loss	(228)		(192)
Securities Available For Sale, Fair Value	469,547	183,729	147,866
Non-Agency Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	2,679	31	37
Securities Available For Sale, Gross Unrealized Gains	50		1
Securities Available For Sale, Gross Unrealized Loss		(1)
Securities Available For Sale, Fair Value	2,729	30	38
States Of The U.S. And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	23,592	38,509	57,830
Securities Available For Sale, Gross Unrealized Gains	1,232	1,841	934
Securities Available For Sale, Gross Unrealized Loss			(26)
Securities Available For Sale, Fair Value	24,824	40,350	58,738
Collateralized Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	34,765	19,224	19,288
Securities Available For Sale, Gross Unrealized Gains	967
Securities Available For Sale, Gross Unrealized Loss	(13,276)	(13,226)	(13,314)
Securities Available For Sale, Fair Value	22,456	5,998	5,974
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	21,790	6,863	12,989
Securities Available For Sale, Gross Unrealized Gains	695
Securities Available For Sale, Gross Unrealized Loss	(972)	(1,666)	(1,744)
Securities Available For Sale, Fair Value	21,513	5,197	11,245
Debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	1,168,885	644,065	742,425
Securities Available For Sale, Gross Unrealized Gains	16,396	9,572	9,475
Securities Available For Sale, Gross Unrealized Loss	(14,605)	(14,893)	(15,964)
Securities Available For Sale, Fair Value	1,170,676	638,744	735,936
Equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities Available For Sale, Amortized Cost	1,554	1,593	1,867
Securities Available For Sale, Gross Unrealized Gains	462	257	381
Securities Available For Sale, Gross Unrealized Loss	(9)	(23)	(59)
Securities Available For Sale, Fair Value	$ 2,007	$ 1,827	$ 2,189

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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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