Investment Securities (Tables)

12 Months Ended

Dec. 31, 2011

Investment Securities [Abstract]

Amortized Cost, Unrealized Gains And Losses, And Fair Value Of Investment Securities

December 31, 2011
(in thousands)
	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
AVAILABLE FOR SALE:
U.S. Treasury and agencies	$	117,232	$	1,234	$	(1	)	$	118,465
Obligations of states and political subdivisions		237,302		16,264		(13	)		253,553
Residential mortgage-backed securities and collateralized mortgage obligations		2,755,153		43,152		(3,950	)		2,794,355
Other debt securities		151		—		(17	)		134
Investments in mutual funds and other equity securities		1,959		112		—			2,071
	$	3,111,797	$	60,762	$	(3,981	)	$	3,168,578
HELD TO MATURITY:
Obligations of states and political subdivisions	$	1,335	$	2	$	—		$	1,337
Residential mortgage-backed securities and collateralized mortgage obligations		3,379		120		(77	)		3,422
	$	4,714	$	122	$	(77	)	$	4,759

December 31, 2010

(in thousands)

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
AVAILABLE FOR SALE:
U.S. Treasury and agencies	$	117,551	$	1,239	$	(1	)	$	118,789
Obligations of states and political subdivisions		213,129		4,985		(1,388	)		216,726
Residential mortgage-backed securities and collateralized mortgage obligations		2,543,974		57,506		(19,976	)		2,581,504
Other debt securities		152		—		—			152
Investments in mutual funds and other equity securities		1,959		50		—			2,009
	$	2,876,765	$	63,780	$	(21,365	)	$	2,919,180
HELD TO MATURITY:
Obligations of states and political subdivisions	$	2,370	$	5	$	—		$	2,375
Residential mortgage-backed securities and collateralized mortgage obligations		2,392		216		(209	)		2,399
	$	4,762	$	221	$	(209	)	$	4,774

Schedule Of Fair Value And Unrealized Losses Of Securities

December 31, 2011

(in thousands)

	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
AVAILABLE FOR SALE:
U.S. Treasury and agencies	$	—	$	—	$	85	$	1	$	85	$	1
Obligations of states and political subdivisions		516		13		—		—		516		13
Residential mortgage-backed securities and collateralized mortgage obligations		489,475		3,160		52,222		790		541,697		3,950
Other debt securities		—		—		134		17		134		17
Total temporarily impaired securities	$	489,991	$	3,173	$	52,441	$	808	$	542,432	$	3,981
HELD TO MATURITY:
Residential mortgage-backed securities and collateralized mortgage obligations	$	—	$	—	$	602	$	77	$	602	$	77
Total temporarily impaired securities	$	—	$	—	$	602	$	77	$	602	$	77

December 31, 2010

(in thousands)

	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
AVAILABLE FOR SALE:
U.S. Treasury and agencies	$	—	$	—	$	110	$	1	$	110	$	1
Obligations of states and political subdivisions		60,110		1,366		1,003		22		61,113		1,388
Residential mortgage-backed securities and collateralized mortgage obligations		1,238,483		19,968		1,539		8		1,240,022		19,976
Total temporarily impaired securities	$	1,298,593	$	21,334	$	2,652	$	31	$	1,301,245	$	21,365
HELD TO MATURITY:
Residential mortgage-backed securities and collateralized mortgage obligations	$	—	$	—	$	658	$	209	$	658	$	209
Total temporarily impaired securities	$	—	$	—	$	658	$	209	$	658	$	209

Other-Than-Temporary Impairment Losses, Investment Securities

	2011				2010				2009
	Held To Maturity		Available For Sale		Held To Maturity		Available For Sale		Held To Maturity			Available For Sale
Total other-than-temporary impairment losses	$	190	$	—	$	93	$	—	$	12,317		$	239
Portion of other-than-temporary impairment losses transferred from (recognized in) other comprehensive income(1)		169		—		321		—		(1,983	)		—
Net impairment losses recognized in earnings(2)	$	359	$	—	$	414	$	—	$	10,334		$	239

(1) Represents other-than-temporary impairment losses related to all other factors.

(2) Represents other-than-temporary impairment losses related to credit losses.

Summary Of Significant Inputs Used To Estimate Credit Loss On Non-Agency Collateralized Mortgage Obligations

	2011									2010
	Range						Weighted			Range						Weighted Average
	Minimum			Maximum			Average			Minimum			Maximum
Constant prepayment rate		10.0	%		20.0	%		14.0	%		5.0	%		20.0	%		14.9	%
Collateral default rate		5.0	%		60.0	%		22.6	%		5.0	%		15.0	%		10.6	%
Loss severity		27.5	%		50.0	%		32.5	%		25.0	%		55.0	%		37.9	%

Roll Forward Of Credit Losses Of Held-To-Maturity Securities Written Down As Other-Than-Temporary Impairment Recognized In Earnings And Other Comprehensive Income

	2011			2010
Balance, beginning of period	$	12,778		$	12,364
Additions:
Subsequent OTTI credit losses		359			414
Reductions:
Securities sold, matured or paid-off		(3,563	)		—
Balance, end of period	$	9,574		$	12,778

Schedule Of Maturities Of Investment Securities

(in thousands)
	Available For Sale				Held To Maturity
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
AMOUNTS MATURING IN:
Three months or less	$	22,142	$	22,217	$	—	$	—
Over three months through twelve months		424,824		429,396		330		331
After one year through five years		2,272,876		2,310,113		1,096		1,155
After five years through ten years		310,639		323,164		1,023		1,010
After ten years		79,357		81,617		2,265		2,263
Other investment securities		1,959		2,071		—		—
	$	3,111,797	$	3,168,578	$	4,714	$	4,759

Gross Realized Gains And Losses On Sales Of Available For Sale Securities

(in thousands)
	2011				2010				2009
	Gains		Losses		Gains		Losses		Gains		Losses
U.S. Treasury and agencies	$	—	$	—	$	—	$	1	$	—	$	—
Obligations of states and political subdivisions		8		—		3		7		—		1
Residential mortgage-backed securities and collateralized mortgage obligations		8,544		817		2,331		—		9,409		591
	$	8,552	$	817	$	2,334	$	8	$	9,409	$	592

Investment Securities Pledged To Secure Borrowings And Public Deposits

(in thousands)
	Amortized Cost		Fair Value
To Federal Home Loan Bank to secure borrowings	$	183,909	$	190,176
To state and local governments to secure public deposits		738,780		759,019
Other securities pledged		191,740		194,200
Total pledged securities	$	1,114,429	$	1,143,395