SECURITIES (Tables)

9 Months Ended

Sep. 30, 2017

SECURITIES [Abstract]

Amortized Cost And Estimated Fair Values Of Available-For-Sale Securities

		September 30, 2017
			Gross	Gross	Estimated
		Amortized	Unrealized	Unrealized	Fair
		Cost	Gains	Losses	Value
	(In thousands)
U.S. Government agencies		$   1,693,102	$           268	$        6,184	$   1,687,186
U.S. Government agency issued residential mortgage-backed securities		157,868	1,288	1,265	157,891
U.S. Government agency issued commercial mortgage-backed securities		153,157	1,400	1,048	153,509
Obligations of states and political subdivisions		316,374	14,032	2,092	328,314
FHLB and other securities		32,791	276	-	33,067
Total		$   2,353,292	$      17,264	$      10,589	$   2,359,967

		December 31, 2016
			Gross	Gross	Estimated
		Amortized	Unrealized	Unrealized	Fair
		Cost	Gains	Losses	Value
	(In thousands)
U.S. Government agencies		$   1,794,231	$        1,261	$        6,065	$   1,789,427
U.S. Government agency issued residential  mortgage-backed securities		176,476	1,665	1,898	176,243
U.S. Government agency issued commercial mortgage-backed securities		171,840	1,648	1,209	172,279
Obligations of states and political subdivisions		346,609	15,547	2,151	360,005
FHLB and other securities		32,436	1,286	-	33,722
Total		$   2,521,592	$      21,407	$      11,323	$   2,531,676

	September 30, 2016
		Gross	Gross	Estimated
	Amortized	Unrealized	Unrealized	Fair
	Cost	Gains	Losses	Value
	(In thousands)
U.S. Government agencies	$   1,686,637	$        5,330	$           101	$   1,691,866
U.S. Government agency issued residential mortgage-backed securities	181,307	2,887	99	184,095
U.S. Government agency issued commercial mortgage-backed securities	175,078	3,831	82	178,827
Obligations of states and political subdivisions	366,039	21,871	2,915	384,995
FHLB and other securities	27,388	1,028	-	28,416
Total	$   2,436,449	$      34,947	$        3,197	$   2,468,199

Amortized Cost And Estimated Fair Value Of Available-For-Sale Securities By Contractual Maturity

	September 30, 2017
		Estimated	Weighted
	Amortized	Fair	Average
	Cost	Value	Yield
	(Dollars in thousands)
Maturing in one year or less	$      595,396	$      595,218	1.21	%
Maturing after one year through five years	1,170,245	1,165,247	1.40
Maturing after five years through ten years	60,417	61,041	5.94
Maturing after ten years	216,209	227,061	5.13
Mortgage-backed securities	311,025	311,400	2.18
Total	$   2,353,292	$   2,359,967

Temporarily Impaired Available-For-Sale Securities With Continuous Unrealized Loss Positions

	September 30, 2017
	Continuous Unrealized Loss Position
	Less Than 12 Months		12 Months or Longer		Total
	Fair	Unrealized	Fair	Unrealized	Fair	Unrealized
	Value	Losses	Value	Losses	Value	Losses
	(In thousands)
U.S. Government agencies	$  1,013,354	$        3,213	$    335,579	$        2,971	$  1,348,933	$        6,184
U.S. Government agency issued residential mortgage-backed securities	45,264	365	34,636	900	79,900	1,265
U.S. Government agency issued commercial mortgage-backed securities	89,351	684	34,176	364	123,527	1,048
Obligations of states and political subdivisions	8,048	21	7,828	2,071	15,876	2,092
Total	$  1,156,017	$        4,283	$    412,219	$        6,306	$  1,568,236	$      10,589

	December 31, 2016
	Continuous Unrealized Loss Position
	Less Than 12 Months		12 Months or Longer		Total
	Fair	Unrealized	Fair	Unrealized	Fair	Unrealized
	Value	Losses	Value	Losses	Value	Losses
	(In thousands)
U.S. Government agencies	$  1,082,573	$        6,065	$                -	$                -	$  1,082,573	$        6,065
U.S. Government agency issued residential mortgage-backed securities	71,599	1,783	15,375	115	86,974	1,898
U.S. Government agency issued commercial mortgage-backed securities	129,940	1,084	14,385	125	144,325	1,209
Obligations of states and political subdivisions	46,798	2,151	-	-	46,798	2,151
Total	$  1,330,910	$      11,083	$      29,760	$           240	$  1,360,670	$      11,323