INVESTMENT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2012

INVESTMENT SECURITIES [Abstract]

Amortized Cost and Estimated Fair Value of Investment Securities

The amortized cost and estimated fair value of investment securities as of March 31, 2012 and December 31, 2011 are as follows:

	March 31, 2012								December 31, 2011
			Gross		Gross		Estimated				Gross		Gross		Estimated
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
(000's omitted)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
Held-to-Maturity Portfolio:
U.S. Treasury and agency securities	$	546,636	$	50,127	$	1,968	$	594,795	$	448,260	$	56,800	$	0	$	505,060
Obligations of state and political subdivisions		70,987		5,515		0		76,502		69,623		5,088		0		74,711
Government agency mortgage-backed securities		32,083		1,696		0		33,779		35,576		2,452		0		38,028
Corporate debt securities		2,940		0		30		2,910		0		0		0		0
Other securities		27		0		0		27		36		0		0		36
Total held-to-maturity portfolio	$	652,673	$	57,338	$	1,998	$	708,013	$	553,495	$	64,340	$	0	$	617,835
Available-for-Sale Portfolio:
U.S. Treasury and agency securities	$	927,036	$	49,971	$	104	$	976,903		463,922	$	56,626	$	0	$	520,548
Obligations of state and political subdivisions		614,466		28,162		2,130		640,498		543,527	$	29,721	$	236		573,012
Government agency mortgage-backed securities		294,686		19,416		25		314,077		310,541		20,840		2		331,379
Pooled trust preferred securities		67,087		0		19,702		47,385		68,115		0		24,269		43,846
Government agency collateralized mortgage obligations		41,726		1,655		71		43,310		45,481		1,572		110		46,943
Corporate debt securities		21,495		1,294		0		22,789		21,495		1,360		0		22,855
Marketable equity securities		381		84		47		418		380		92		82		390
Total available-for-sale portfolio	$	1,966,877	$	100,582	$	22,079	$	2,045,380	$	1,453,461	$	110,211	$	24,699	$	1,538,973
Other Securities:
Federal Home Loan Bank common stock	$	46,534					$	46,534	$	38,343					$	38,343
Federal Reserve Bank common stock		15,450						15,450		15,451						15,451
Other equity securities		5,108						5,108		5,108						5,108
Total other securities	$	67,092					$	67,092	$	58,902					$	58,902

Summary of Investment Securities That Have Been in a Continuous Unrealized Loss Position for Less Than or Greater Than Twelve Months

A summary of investment securities that have been in a continuous unrealized loss position for less than, or greater, than twelve months is as follows:

As of March 31, 2012

	Less than 12 Months						12 Months or Longer						Total
					Gross						Gross						Gross
			Fair		Unrealized				Fair		Unrealized				Fair		Unrealized
(000's omitted)		#	Value		Losses			#	Value		Losses			#	Value		Losses
Held-to-Maturity Portfolio:
U.S. treasury and agency securities		5	$	96,318	$	1,968		0	$	0	$	0		5	$	96,318	$	1,968
Corporate debt securities		2		2,910		30		0		0		0		2		2,910		30
Total held-to-maturity investment portfolio		7		99,228		1,998		0		0		0		7		99,228		1,998
Available-for-Sale Portfolio:
U.S. treasury and agency securities		2		34,365		104		0		0		0		2		34,365		104
Obligations of state and political subdivisions		116		80,605		2,096		6		6,238		34		122		86,843		2,130
Pooled trust preferred securities		0		0		0		3		47,385		19,702		3		47,385		19,702
Government agency mortgage-backed securities		3		3,421		24		1		30		1		4		3,451		25
Government agency collateralized mortgage obligations		2		49		0		9		5,157		71		11		5,206		71
Marketable equity securities		1		217		44		3		13		3		4		170		47
Total available-for-sale investment portfolio		124		118,597		2,268		22		58,823		19,811		146		177,420		22,079
Total investment portfolio		131	$	217,825	$	4,266		22	$	58,823	$	19,811		153	$	276,648	$	24,077

As of December 31, 2011

	Less than 12 Months			12 Months or Longer			Total
			Gross			Gross			Gross
		Fair	Unrealized		Fair	Unrealized		Fair	Unrealized
(000's omitted)	#	Value	Losses	#	Value	Losses	#	Value	Losses
Available-for-Sale Portfolio:
Obligations of state and political subdivisions	2	$211	$0	6	$6,038	$236	8	$6,249	$236
Government agency mortgage-backed securities	3	2,415	2	0	0	0	3	2,415	2
Pooled trust preferred securities	0	0	0	3	43,846	24,269	3	43,846	24,269
Government agency collateralized mortgage obligations	17	6,648	110	0	0	0	17	6,648	110
Marketable equity securities	1	123	78	3	12	4	4	135	82
Total available-for-sale/investment portfolio	23	$9,397	$190	12	$49,896	$24,509	35	$59,293	$24,699

	Less than 12 Months						12 Months or Longer						Total
					Gross						Gross						Gross
			Fair		Unrealized				Fair		Unrealized				Fair		Unrealized
(000's omitted)		#	Value		Losses			#	Value		Losses			#	Value		Losses
Available-for-Sale Portfolio:
Obligations of state and political subdivisions		2	$	211	$	0		6	$	6,038	$	236		8	$	6,249	$	236
Pooled trust preferred securities		0		0		0		3		43,846		24,269		3		43,846		24,269
Government agency mortgage-backed securities		3		2,415		2		0		0		0		3		2,415		2
Government agency collateralized mortgage obligations		17		6,648		110		0		0		0		17		6,648		110
Marketable equity securities		1		123		78		3		12		4		4		135		82
Total available-for-sale/investment portfolio		23	$	9,397	$	190		12	$	49,896	$	24,509		35	$	59,293	$	24,699

Amortized Cost and Estimated Fair Value of Debt Securities by Contractual Maturity

The amortized cost and estimated fair value of debt securities at March 31, 2012, by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.  Securities not due at a single maturity date are shown separately.

	Held-to-Maturity				Available-for-Sale
	Amortized		Fair		Amortized		Fair
(000's omitted)	Cost		Value		Cost		Value
Due in one year or less	$	12,525	$	12,615	$	31,089	$	31,342
Due after one through five years		279,894		307,866		228,714		243,293
Due after five years through ten years		163,599		183,466		885,741		917,083
Due after ten years		164,572		170,287		484,540		495,857
Subtotal		620,590		674,234		1,630,084		1,687,575
Government agency collateralized mortgage obligations		0		0		41,726		43,310
Government agency mortgage-backed securities		32,083		33,779		294,686		314,077
Total	$	652,673	$	708,013	$	1,966,496	$	2,044,962