Securities (Tables)

6 Months Ended

Jun. 30, 2014

Investments Debt And Equity Securities [Abstract]

Schedule of Fair Value and Amortized Cost of Available-for-sale and Held-to-maturity Securities

The following table presents the fair value and amortized cost of available-for-sale and held-to-maturity securities:

	June 30, 2014									December 31, 2013
(unaudited, in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
Available-for-sale
Obligations of government agencies	$	79,164	$	382	$	(644	)	$	78,902	$	75,164	$	6	$	(1,938	)	$	73,232
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies		772,918		4,114		(9,550	)		767,482		707,000		3,191		(15,924	)		694,267
Obligations of states and political subdivisions		104,553		5,700		(14	)		110,239		112,536		4,165		(355	)		116,346
Corporate debt securities		36,731		260		(99	)		36,892		38,777		174		(470	)		38,481
Total debt securities	$	993,366	$	10,456	$	(10,307	)	$	993,515	$	933,477	$	7,536	$	(18,687	)	$	922,326
Equity securities		11,270		1,294		—			12,564		10,597		1,463		—			12,060
Total available-for-sale securities	$	1,004,636	$	11,750	$	(10,307	)	$	1,006,079	$	944,074	$	8,999	$	(18,687	)	$	934,386
Held-to-maturity
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies	$	88,897	$	3,705	$	(501	)	$	92,101	$	99,409	$	2,804	$	(1,023	)	$	101,190
Obligations of states and political subdivisions		513,058		20,866		(3,206	)		530,718		496,396		10,158		(13,906	)		492,648
Corporate debt securities		5,740		66		(85	)		5,721		2,715		—		(245	)		2,470
Total held-to-maturity securities	$	607,695	$	24,637	$	(3,792	)	$	628,540	$	598,520	$	12,962	$	(15,174	)	$	596,308
Total securities	$	1,612,331	$	36,387	$	(14,099	)	$	1,634,619	$	1,542,594	$	21,961	$	(33,861	)	$	1,530,694

Schedule of Fair Value of Available-for-sale and Held-to-maturity Securities by Contractual Maturity

The following table presents the fair value of available-for-sale and held-to-maturity securities by contractual maturity at June 30, 2014. In some instances, the issuers may have the right to call or prepay obligations without penalty prior to the contractual maturity date.

	June 30, 2014
(unaudited, in thousands)	One Year or less		One to Five Years		Five to Ten Years		After Ten Years		Mortgage-backed and Equity		Total
Available-for-sale
Obligations of government agencies	$	313	$	9,833	$	26,123	$	42,633	$	—	$	78,902
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies (1)		—		—		—		—		767,482		767,482
Obligations of states and political subdivisions		7,072		43,257		21,615		38,295		—		110,239
Corporate debt securities		4,018		15,939		12,044		4,891		—		36,892
Equity securities (2)		—		—		—		—		12,564		12,564
Total available-for-sale securities	$	11,403	$	69,029	$	59,782	$	85,819	$	780,046	$	1,006,079
Held-to-maturity (3)
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies (1)	$	—	$	—	$	—	$	—	$	92,101	$	92,101
Obligations of states and political subdivisions		4,743		12,390		178,977		334,608		—		530,718
Corporate debt securities		—		—		5,721		—		—		5,721
Total held-to-maturity securities	$	4,743	$	12,390	$	184,698	$	334,608	$	92,101	$	628,540
Total securities	$	16,146	$	81,419	$	244,480	$	420,427	$	872,147	$	1,634,619

⁽¹⁾  Mortgage-backed and collateralized mortgage securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds.

⁽²⁾ Equity securities, which have no stated maturity, are not assigned a maturity category.

⁽³⁾  The held-to-maturity portfolio is carried at an amortized cost of $607.7 million.

Schedule of Unrealized Losses on Investment Securities

The following tables provide information on unrealized losses on investment securities that have been in an unrealized loss position for less than twelve months and twelve months or more as of June 30, 2014 and December 31, 2013:

	June 30, 2014
	Less than 12 months							12 months or more							Total
	Fair		Unrealized			# of		Fair		Unrealized			# of		Fair		Unrealized			# of
(unaudited, dollars in thousands)	Value		Losses			Securities		Value		Losses			Securities		Value		Losses			Securities
Obligations of government agencies	$	18,919	$	(124	)		5	$	19,790	$	(520	)		5	$	38,709	$	(644	)		10
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies		191,506		(1,380	)		37		239,724		(8,671	)		42		431,230		(10,051	)		79
Obligations of states and political subdivisions		20,790		(107	)		34		115,199		(3,113	)		177		135,989		(3,220	)		211
Corporate debt securities		4,996		(4	)		1		4,525		(180	)		2		9,521		(184	)		3
Total temporarily impaired securities	$	236,211	$	(1,615	)		77	$	379,238	$	(12,484	)		226	$	615,449	$	(14,099	)		303
	December 31, 2013
	Less than 12 months							12 months or more							Total
	Fair		Unrealized			# of		Fair		Unrealized			# of		Fair		Unrealized			# of
(unaudited, dollars in thousands)	Value		Losses			Securities		Value		Losses			Securities		Value		Losses			Securities
Obligations of government agencies	$	54,356	$	(1,911	)		15	$	5,083	$	(27	)		2	$	59,439	$	(1,938	)		17
Residential mortgage-backed securities and collateralized mortgage obligations of government agencies		513,495		(14,639	)		89		37,002		(2,308	)		11		550,497		(16,947	)		100
Obligations of states and political subdivisions		181,667		(10,830	)		277		47,793		(3,431	)		76		229,460		(14,261	)		353
Corporate debt securities		19,837		(560	)		7		2,845		(155	)		1		22,682		(715	)		8
Total temporarily impaired securities	$	769,355	$	(27,940	)		388	$	92,723	$	(5,921	)		90	$	862,078	$	(33,861	)		478