Investment Securities (Tables)

3 Months Ended

Mar. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities

The following is a summary of the amortized cost and fair value of investment securities available-for-sale and investment securities held-to-maturity at March 31, 2015, December 31, 2014 and March 31, 2014:

	Investment Securities Available-for-Sale
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
	(In thousands)
March 31, 2015
U.S. Treasury securities	$	8,271	$	31	$	—	$	8,302
Government sponsored agencies	249,642		889		101		250,430
State and political subdivisions	31,701		624		3		32,322
Residential mortgage-backed securities	218,299		1,358		56		219,601
Collateralized mortgage obligations	133,713		305		718		133,300
Corporate bonds	34,925		136		64		34,997
Preferred stock	1,389		303		—		1,692
Total	$	677,940	$	3,646	$	942	$	680,644
December 31, 2014
U.S. Treasury securities	$	8,272	$	—	$	13	$	8,259
Government sponsored agencies	263,658		356		511		263,503
State and political subdivisions	45,157		1,087		17		46,227
Residential mortgage-backed securities	240,465		885		1,543		239,807
Collateralized mortgage obligations	145,316		261		1,194		144,383
Corporate bonds	44,930		213		48		45,095
Preferred stock	1,389		201		—		1,590
Total	$	749,187	$	3,003	$	3,326	$	748,864
March 31, 2014
Government sponsored agencies	$	91,613	$	295	$	298	$	91,610
State and political subdivisions	42,369		1,408		—		43,777
Residential mortgage-backed securities	291,187		1,023		3,472		288,738
Collateralized mortgage obligations	167,622		393		1,296		166,719
Corporate bonds	65,003		505		93		65,415
Preferred stock	1,389		170		—		1,559
Total	$	659,183	$	3,794	$	5,159	$	657,818

Held-to-maturity Securities

	Investment Securities Held-to-Maturity
	Amortized Cost		Unrealized Gains		Unrealized Losses		Fair Value
	(In thousands)
March 31, 2015
State and political subdivisions	$	370,950	$	6,852	$	4,926	$	372,876
Trust preferred securities	10,500		—		3,200		7,300
Total	$	381,450	$	6,852	$	8,126	$	380,176
December 31, 2014
State and political subdivisions	$	305,913	$	7,294	$	4,557	$	308,650
Trust preferred securities	10,500		—		3,410		7,090
Total	$	316,413	$	7,294	$	7,967	$	315,740
March 31, 2014
State and political subdivisions	$	267,599	$	5,331	$	6,983	$	265,947
Trust preferred securities	10,500		—		4,040		6,460
Total	$	278,099	$	5,331	$	11,023	$	272,407

Amortized cost and fair value of debt securities by contractual maturity

The following is a summary of the amortized cost and fair value of investment securities at March 31, 2015, by maturity, for both available-for-sale and held-to-maturity investment securities. The maturities of residential mortgage-backed securities and collateralized mortgage obligations are based on scheduled principal payments. The maturities of all other debt securities are based on final contractual maturity.

	March 31, 2015
	Amortized Cost		Fair Value
	(In thousands)
Investment Securities Available-for-Sale:
Due in one year or less	$	180,558	$	180,869
Due after one year through five years	442,088		443,752
Due after five years through ten years	50,902		51,302
Due after ten years	3,003		3,029
Preferred stock	1,389		1,692
Total	$	677,940	$	680,644
Investment Securities Held-to-Maturity:
Due in one year or less	$	35,293	$	35,365
Due after one year through five years	171,557		172,699
Due after five years through ten years	120,799		122,512
Due after ten years	53,801		49,600
Total	$	381,450	$	380,176

Summary of continuous unrealized loss position of securities

The following schedule summarizes information for both available-for-sale and held-to-maturity investment securities with gross unrealized losses at March 31, 2015, December 31, 2014 and March 31, 2014, aggregated by category and length of time that individual securities have been in a continuous unrealized loss position.

	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(In thousands)
March 31, 2015
U.S. Treasury securities	$	—	$	—	$	—	$	—	$	—	$	—
Government sponsored agencies	27,889		64		18,896		37		46,785		101
State and political subdivisions	156,010		1,989		49,839		2,940		205,849		4,929
Residential mortgage-backed securities	82,303		28		3,847		28		86,150		56
Collateralized mortgage obligations	22,694		22		41,061		696		63,755		718
Corporate bonds	4,989		11		14,946		53		19,935		64
Trust preferred securities	—		—		7,300		3,200		7,300		3,200
Total	$	293,885	$	2,114	$	135,889	$	6,954	$	429,774	$	9,068
December 31, 2014
U.S. Treasury securities	$	8,259	$	13	$	—	$	—	$	8,259	$	13
Government sponsored agencies	166,963		406		31,927		105		198,890		511
State and political subdivisions	62,310		3,348		36,847		1,226		99,157		4,574
Residential mortgage-backed securities	17,276		52		180,194		1,491		197,470		1,543
Collateralized mortgage obligations	63,077		179		31,620		1,015		94,697		1,194
Corporate bonds	—		—		14,952		48		14,952		48
Trust preferred securities	—		—		7,090		3,410		7,090		3,410
Total	$	317,885	$	3,998	$	302,630	$	7,295	$	620,515	$	11,293
March 31, 2014
Government sponsored agencies	$	45,396	$	110	$	15,204	$	188	$	60,600	$	298
State and political subdivisions	79,787		4,942		56,180		2,041		135,967		6,983
Residential mortgage-backed securities	247,397		3,472		—		—		247,397		3,472
Collateralized mortgage obligations	76,900		885		12,833		411		89,733		1,296
Corporate bonds	—		—		14,907		93		14,907		93
Trust preferred securities	—		—		6,460		4,040		6,460		4,040
Total	$	449,480	$	9,409	$	105,584	$	6,773	$	555,064	$	16,182