INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 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 December 31 are as follows:

	2012								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	$	548,634	$	59,081	$	0	$	607,715	$	448,260	$	56,800	$	0	$	505,060
Obligations of state and political subdivisions		65,742		5,850		0		71,592		69,623		5,088		0		74,711
Government agency mortgage-backed securities		20,578		1,079		0		21,657		35,576		2,452		0		38,028
Corporate debt securities		2,924		53		0		2,977		0		0		0		0
Other securities		16		0		0		16		36		0		0		36
Total held-to-maturity portfolio	$	637,894	$	66,063	$	0	$	703,957	$	553,495	$	64,340	$	0		617,835
Available-for-Sale Portfolio:
U.S. Treasury and agency securities	$	988,217	$	91,040	$	0	$	1,079,257	$	463,922	$	56,626	$	0	$	520,548
Obligations of state and political subdivisions		629,883		33,070		61		662,892		543,527		29,721		236		573,012
Government agency mortgage-backed securities		253,013		16,989		51		269,951		310,541		20,840		2		331,379
Pooled trust preferred securities		61,979		0		12,379		49,600		68,115		0		24,269		43,846
Government agency collateralized mortgage obligations		32,359		1,579		3		33,935		45,481		1,572		110		46,943
Corporate debt securities		24,136		1,265		44		25,357		21,495		1,360		0		22,855
Marketable equity securities		351		94		43		402		380		92		82		390
Total available-for-sale portfolio	$	1,989,938	$	144,037	$	12,581	$	2,121,394	$	1,453,461	$	110,211	$	24,699	$	1,538,973
Other Securities:
Federal Home Loan Bank common stock	$	38,111					$	38,111	$	38,343					$	38,343
Federal Reserve Bank common stock		16,050						16,050		15,451						15,451
Other equity securities		5,078						5,078		5,108						5,108
Total other securities	$	59,239					$	59,239	$	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 December 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
Available-for-Sale Portfolio:
Obligations of state and political subdivisions	19	$	11,503	$	61	0		0		0	19	$	11,503	$	61
Pooled trust preferred securities	0		0		0	3		49,600		12,379	3		49,600		12,379
Government agency mortgage-backed securities	8		14,354		51	0		0		0	8		14,354		51
Corporate debt securities	1		2,905		44	0		0		0	1		2,905		44
Government agency collateralized mortgage obligations	4		426		2	2		1,041		1	6		1,467		3
Marketable equity securities	0		0		0	1		158		43	1		158		43
Total available-for-sale/investment portfolio	32	$	29,188	$	158	6	$	50,799	$	12,423	38	$	79,987	$	12,581

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
Pooled trust preferred securities	0		0		0	3		43,019		24,269	3		43,019		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	$	49,069	$	24,509	35	$	58,466	$	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 December 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	$	18,502	$	18,788	$	40,414	$	41,087
Due after one through five years		269,860		297,891		256,477		279,179
Due after five years through ten years		274,760		304,847		945,139		1,009,240
Due after ten years		54,194		60,774		462,185		487,600
Subtotal		617,316		682,300		1,704,215		1,817,106
Government agency mortgage-back securities		20,578		21,657		253,013		269,951
Government agency collateralized mortgage obligations		0		0		32,359		33,935
Total	$	637,894	$	703,957	$	1,989,587	$	2,120,992

Cash flow information on investment securities

Cash flow information on investment securities for the years ended December 31 is as follows:

(000's omitted)	2012		2011		2010
Gross gains on sales of investment securities	$	350	$	349	$	0
Gross losses on sales of investment securities		59		319		0
Proceeds from the maturities of mortgage-backed securities and CMO's		109,843		97,224		93,171
Purchases of mortgage-backed securities and CMO's		26,292		253,378		9,132