Investment Securities

The following tables present the amortized cost, the gross unrealized gains and losses and the fair value of the Company’s investment securities:



	September 30, 2015
	Amortized Cost		Gross Unrealized			Fair Value
(Dollars in thousands)	Amortized Cost		Gains	Losses		Fair Value
Available-for-sale
U.S. government and federal agency	$	49,712	15	(412	)	49,315
U.S. government sponsored enterprises	98,095		699	(3	)	98,791
State and local governments	903,722		34,084	(6,806	)	931,000
Corporate bonds	360,846		1,219	(1,254	)	360,811
Residential mortgage-backed securities	1,081,926		11,440	(2,289	)	1,091,077
Total available-for-sale	2,494,301		47,457	(10,764	)	2,530,994
Held-to-maturity
State and local governments	651,822		26,470	(5,897	)	672,395
Total held-to-maturity	651,822		26,470	(5,897	)	672,395
Total investment securities	$	3,146,123	73,927	(16,661	)	3,203,389



	December 31, 2014
	Amortized Cost		Gross Unrealized			Fair Value
(Dollars in thousands)	Amortized Cost		Gains	Losses		Fair Value
Available-for-sale
U.S. government and federal agency	$	44	—	—		44
U.S. government sponsored enterprises	21,916		31	(2	)	21,945
State and local governments	962,365		40,173	(4,569	)	997,969
Corporate bonds	313,545		2,059	(750	)	314,854
Residential mortgage-backed securities	1,043,897		11,205	(2,486	)	1,052,616
Total available-for-sale	2,341,767		53,468	(7,807	)	2,387,428
Held-to-maturity
State and local governments	520,997		32,925	(2,976	)	550,946
Total held-to-maturity	520,997		32,925	(2,976	)	550,946
Total investment securities	$	2,862,764	86,393	(10,783	)	2,938,374

The following table presents the amortized cost and fair value of available-for-sale and held-to-maturity securities by contractual maturity at September 30, 2015. Actual maturities may differ from expected or contractual maturities since borrowers have the right to prepay obligations with or without prepayment penalties.



	September 30, 2015
	Available-for-Sale			Held-to-Maturity
(Dollars in thousands)	Amortized Cost		Fair Value	Amortized Cost	Fair Value
Due within one year	$	155,812	156,630	—	—
Due after one year through five years	432,211		433,896	—	—
Due after five years through ten years	151,861		156,083	18,557	18,706
Due after ten years	672,491		693,308	633,265	653,689
	1,412,375		1,439,917	651,822	672,395
Residential mortgage-backed securities ¹	1,081,926		1,091,077	—	—
Total	$	2,494,301	2,530,994	651,822	672,395

__________

¹ Residential mortgage-backed securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds.

Proceeds from sales and calls of investment securities and the associated gains and losses that have been included in earnings are listed below:



	Three Months ended					Nine Months ended
(Dollars in thousands)	September 30, 2015			September 30, 2014		September 30, 2015		September 30, 2014
Available-for-sale
Proceeds from sales and calls of investment securities	$	39,502		166,577		114,123		200,277
Gross realized gains ¹	516			160		598		341
Gross realized losses ¹	(566		)	(221	)	(693	)	(523	)
Held-to-maturity
Proceeds from calls of investment securities	6,697			5,006		16,762		8,936
Gross realized gains ¹	19			—		34		22
Gross realized losses ¹	—			—		(63	)	—

__________

¹ The gain or loss on the sale or call of each investment security is determined by the specific identification method.

Investment securities with an unrealized loss position are summarized as follows:



	September 30, 2015
	Less than 12 Months				12 Months or More			Total
(Dollars in thousands)	Fair Value		Unrealized Loss		Fair Value	Unrealized Loss		Fair Value	Unrealized Loss
Available-for-sale
U.S. government and federal agency	$	46,129	(412	)	2	—		46,131	(412	)
U.S. government sponsored enterprises	4,595		(3	)	—	—		4,595	(3	)
State and local governments	135,878		(1,986	)	137,894	(4,820	)	273,772	(6,806	)
Corporate bonds	131,483		(826	)	10,736	(428	)	142,219	(1,254	)
Residential mortgage-backed securities	222,095		(1,317	)	56,363	(972	)	278,458	(2,289	)
Total available-for-sale	$	540,180	(4,544	)	204,995	(6,220	)	745,175	(10,764	)
Held-to-maturity
State and local governments	$	108,671	(2,389	)	69,625	(3,508	)	178,296	(5,897	)
Total held-to-maturity	$	108,671	(2,389	)	69,625	(3,508	)	178,296	(5,897	)



	December 31, 2014
	Less than 12 Months				12 Months or More			Total
(Dollars in thousands)	Fair Value		Unrealized Loss		Fair Value	Unrealized Loss		Fair Value	Unrealized Loss
Available-for-sale
U.S. government and federal agency	$	—	—		3	—		3	—
U.S. government sponsored enterprises	13,793		(2	)	—	—		13,793	(2	)
State and local governments	91,082		(1,273	)	115,927	(3,296	)	207,009	(4,569	)
Corporate bonds	60,289		(545	)	7,874	(205	)	68,163	(750	)
Residential mortgage-backed securities	192,962		(926	)	78,223	(1,560	)	271,185	(2,486	)
Total available-for-sale	$	358,126	(2,746	)	202,027	(5,061	)	560,153	(7,807	)
Held-to-maturity
State and local governments	$	18,643	(624	)	76,761	(2,352	)	95,404	(2,976	)
Total held-to-maturity	$	18,643	(624	)	76,761	(2,352	)	95,404	(2,976	)

Based on an analysis of its investment securities with unrealized losses as of September 30, 2015 and December 31, 2014, the Company determined that none of such securities had other-than-temporary impairment and the unrealized losses were primarily the result of interest rate changes and market spreads subsequent to acquisition. The fair value of the investment securities is expected to recover as payments are received and the securities approach maturity. At September 30, 2015, management determined that it did not intend to sell investment securities with unrealized losses, and there was no expected requirement to sell any of its investment securities with unrealized losses before recovery of their amortized cost.