INVESTMENT SECURITIES (Tables)

3 Months Ended

Mar. 31, 2019

The amortized cost and estimated fair value of investment securities as of March 31, 2019 and December 31, 2018 are as follows:

	March 31, 2019								December 31, 2018
(000's omitted)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available-for-Sale Portfolio:
U.S. Treasury and agency securities	$	2,033,399	$	6,841	$	5,268	$	2,034,972	$	2,036,474	$	2,190	$	14,911	$	2,023,753
Obligations of state and political subdivisions		423,916		9,319		76		433,159		453,640		6,563		1,049		459,154
Government agency mortgage-backed securities		389,154		2,587		5,198		386,543		390,234		1,526		9,283		382,477
Corporate debt securities		2,572		0		19		2,553		2,588		0		42		2,546
Government agency collateralized mortgage obligations		66,226		88		598		65,716		69,342		60		1,283		68,119
Total available-for-sale portfolio	$	2,915,267	$	18,835	$	11,159	$	2,922,943	$	2,952,278	$	10,339	$	26,568	$	2,936,049

Equity and other Securities:
Equity securities, at fair value	$	251	$	215	$	2	$	464	$	251	$	200	$	19	$	432
Federal Home Loan Bank common stock		6,308		0		0		6,308		8,768		0		0		8,768
Federal Reserve Bank common stock		30,690		0		0		30,690		30,690		0		0		30,690
Other equity securities, at adjusted cost		4,992		750		0		5,742		4,969		750		0		5,719
Total equity and other securities	$	42,241	$	965	$	2	$	43,204	$	44,678	$	950	$	19	$	45,609

A summary of investment securities that have been in a continuous unrealized loss position is as follows:

As of March 31, 2019

	Less than 12 Months						12 Months or Longer						Total
(000's omitted)		#	Fair Value		Gross Unrealized Losses			#	Fair Value		Gross Unrealized Losses			#	Fair Value		Gross Unrealized Losses

Available-for-Sale Portfolio:
U.S. Treasury and agency securities		0	$	0	$	0		48	$	862,482	$	5,268		48	$	862,482	$	5,268
Obligations of state and political subdivisions		3		869		2		20		11,854		74		23		12,723		76
Government agency mortgage-backed securities		9		5,241		6		181		242,566		5,192		190		247,807		5,198
Corporate debt securities		0		0		0		1		2,553		19		1		2,553		19
Government agency collateralized mortgage obligations		1		1		0		39		56,690		598		40		56,691		598
Total available-for-sale investment portfolio		13	$	6,111	$	8		289	$	1,176,145	$	11,151		302	$	1,182,256	$	11,159

Equity and other Securities:
Equity securities, at fair value		1	$	98	$	2		0	$	0	$	0		1	$	98	$	2
Total equity and other securities		1	$	98	$	2		0	$	0	$	0		1	$	98	$	2

As of December 31, 2018

	Less than 12 Months						12 Months or Longer						Total
(000's omitted)		#	Fair Value		Gross Unrealized Losses			#	Fair Value		Gross Unrealized Losses			#	Fair Value		Gross Unrealized Losses

Available-for-Sale Portfolio:
U.S. Treasury and agency securities		7	$	473,082	$	682		64	$	1,213,276	$	14,229		71	$	1,686,358	$	14,911
Obligations of state and political subdivisions		118		55,671		216		97		51,753		833		215		107,424		1,049
Government agency mortgage-backed securities		43		47,708		258		181		253,931		9,025		224		301,639		9,283
Corporate debt securities		0		0		0		1		2,546		42		1		2,546		42
Government agency collateralized mortgage obligations		1		66		0		41		63,112		1,283		42		63,178		1,283
Total available-for-sale investment portfolio		169	$	576,527	$	1,156		384	$	1,584,618	$	25,412		553	$	2,161,145	$	26,568

Equity and other Securities:
Equity securities, at fair value		1	$	82	$	19		0	$	0	$	0		1	$	82	$	19
Total equity and other securities		1	$	82	$	19		0	$	0	$	0		1	$	82	$	19

Securities not due at a single maturity date are shown separately.

	Available-for-Sale
(000's omitted)	Amortized Cost		Fair Value
Due in one year or less	$	76,873	$	76,767
Due after one through five years		2,093,361		2,096,910
Due after five years through ten years		152,168		156,042
Due after ten years		137,485		140,965
Subtotal		2,459,887		2,470,684
Government agency mortgage-backed securities		389,154		386,543
Government agency collateralized mortgage obligations		66,226		65,716
Total	$	2,915,267	$	2,922,943