INVESTMENT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2013

Amortized cost and estimated fair value of investment securities

The amortized cost and estimated fair value of investment securities as of March 31, 2013 and December 31, 2012 are as follows:

	March 31, 2013								December 31, 2012
			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	$	549,301	$	55,429	$	0	$	604,730	$	548,634	$	59,081	$	0	$	607,715
Obligations of state and political subdivisions		62,372		4,955		0		67,327		65,742		5,850		0		71,592
Government agency mortgage-backed securities		17,379		920		0		18,299		20,578		1,079		0		21,657
Corporate debt securities		2,919		61		0		2,980		2,924		53		0		2,977
Other securities		13		0		0		13		16		0		0		16
Total held-to-maturity portfolio	$	631,984	$	61,365	$	0	$	693,349	$	637,894	$	66,063	$	0	$	703,957

Available-for-Sale Portfolio:
U.S. Treasury and agency securities	$	737,785	$	32,035	$	74	$	769,746	$	988,217	$	91,040	$	0	$	1,079,257
Obligations of state and political subdivisions		618,853		28,775		935		646,693		629,883		33,070		61		662,892
Government agency mortgage-backed securities		240,909		12,833		397		253,345		253,013		16,989		51		269,951
Pooled trust preferred securities		57,973		0		10,487		47,486		61,979		0		12,379		49,600
Government agency collateralized mortgage obligations		28,861		1,775		0		30,636		32,359		1,579		3		33,935
Corporate debt securities		24,109		1,217		38		25,288		24,136		1,265		44		25,357
Marketable equity securities		351		119		30		440		351		94		43		402
Total available-for-sale portfolio	$	1,708,841	$	76,754	$	11,961	$	1,773,634	$	1,989,938	$	144,037	$	12,581	$	2,121,394

Other Securities:
Federal Home Loan Bank common stock	$	21,612					$	21,612	$	38,111					$	38,111
Federal Reserve Bank common stock		16,050						16,050		16,050						16,050
Other equity securities		4,840						4,840		5,078						5,078
Total other securities	$	42,502					$	42,502	$	59,239					$	59,239

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, 2013

	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:
U.S. Treasury and agency securities		3	$	79,672	$	74		0	$	0	$	0		3	$	79,672	$	74
Obligations of state and political subdivisions		87		53,061		919		2		929		16		89		53,990		935
Government agency mortgage-backed securities		14		30,772		397		0		0		0		14		30,772		397
Pooled trust preferred securities		0		0		0		3		47,486		10,487		3		47,486		10,487
Corporate debt securities		1		2,896		38		0		0		0		1		2,896		38
Government agency collateralized mortgage obligations		0		0		0		1		9		0		1		9		0
Marketable equity securities		0		0		0		1		171		30		1		171		30
Total available-for-sale/investment portfolio		105	$	166,401	$	1,428		7	$	48,595	$	10,533		112	$	214,996	$	11,961

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

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, 2013, 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	$	18,343	$	18,495	$	40,228	$	40,612
Due after one through five years		269,592		296,031		154,607		161,312
Due after five years through ten years		275,681		303,861		787,866		828,678
Due after ten years		50,989		56,663		456,019		458,611
Subtotal		614,605		675,050		1,438,720		1,489,213
Government agency collateralized mortgage obligations		0		0		28,861		30,636
Government agency mortgage-backed securities		17,379		18,299		240,909		253,345
Total	$	631,984	$	693,349	$	1,708,490	$	1,773,194