INVESTMENTS IN DEBT AND EQUITY SECURITIES

Securities Available for Sale. The amortized cost, contractual maturity, gross unrealized gains and losses and fair value of investment securities available for sale at March 31, 2014 and December 31, 2013 were as follows:



	Maturity									Total Amortized Cost	Gross				Weighted Average Yield
	1 Year			1-5		5-10		After			Unrealized			Fair
	or Less			Years		Years		10 Years			Gains	Losses		Value
	(dollars expressed in thousands)
March 31, 2014:
Carrying value:
U.S. Government sponsored agencies	$	8,418		30,058		20,136		132,248		190,860	4,281	(47	)	195,094	1.37	%
Residential mortgage-backed	282			28,277		82,445		891,319		1,002,323	13,662	(12,540	)	1,003,445	2.37
Commercial mortgage-backed	—			—		789		—		789	62	—		851	4.95
State and political subdivisions	1,367			1,681		200		28,417		31,665	67	(392	)	31,340	1.23
Corporate notes	5,000			121,153		45,131		—		171,284	5,066	(599	)	175,751	2.82
Equity investments	—			—		—		1,750		1,750	—	(59	)	1,691	2.13
Total	$	15,067		181,169		148,701		1,053,734		1,398,671	23,138	(13,637	)	1,408,172	2.26
Fair value:
Debt securities	$	15,135		186,936		148,797		1,055,613
Equity securities	—			—		—		1,691
Total	$	15,135		186,936		148,797		1,057,304

Weighted average yield	2.21		%	2.39	%	2.10	%	2.26	%

December 31, 2013:
Carrying value:
U.S. Government sponsored agencies	$	8,450		40,243		88,666		135,679		273,038	3,525	(664	)	275,899	1.34	%
Residential mortgage-backed	—			43,943		115,731		951,454		1,111,128	12,873	(18,214	)	1,105,787	2.32
Commercial mortgage-backed	—			—		793		—		793	63	—		856	4.94
State and political subdivisions	1,369			2,035		200		28,432		32,036	81	(560	)	31,557	1.26
Corporate notes	4,980			140,575		45,132		—		190,687	5,777	(261	)	196,203	2.69
Equity investments	—			—		—		1,500		1,500	—	(57	)	1,443	2.17
Total	$	14,799		226,796		250,522		1,117,065		1,609,182	22,319	(19,756	)	1,611,745	2.18
Fair value:
Debt securities	$	14,927		233,338		250,860		1,111,177
Equity securities	—			—		—		1,443
Total	$	14,927		233,338		250,860		1,112,620

Weighted average yield	2.17		%	2.23	%	1.81	%	2.24	%

Securities Held to Maturity. The amortized cost, contractual maturity, gross unrealized gains and losses and fair value of investment securities held to maturity at March 31, 2014 and December 31, 2013 were as follows:



	Maturity									Total Amortized Cost	Gross				Weighted Average Yield
	1 Year			1-5		5-10		After			Unrealized			Fair
	or Less			Years		Years		10 Years			Gains	Losses		Value
	(dollars expressed in thousands)
March 31, 2014:
Carrying value:
U.S. Government sponsored agencies	$	—		—		14,373		—		14,373	—	(135	)	14,238	1.16	%
Residential mortgage-backed	—			79,836		115,139		507,272		702,247	622	(14,101	)	688,768	1.91
State and political subdivisions	445			574		—		1,033		2,052	1	(82	)	1,971	1.63
Total	$	445		80,410		129,512		508,305		718,672	623	(14,318	)	704,977	1.89
Fair value:
Debt securities	$	445		80,347		128,038		496,147

Weighted average yield	2.85		%	2.01	%	1.42	%	2.00	%

December 31, 2013:
Carrying value:
U.S. Government sponsored agencies	$	—		—		16,119		—		16,119	—	(153	)	15,966	1.14	%
Residential mortgage-backed	—			16,327		182,933		522,504		721,764	441	(21,206	)	700,999	1.88
State and political subdivisions	640			575		55		1,033		2,303	2	(87	)	2,218	1.93
Total	$	640		16,902		199,107		523,537		740,186	443	(21,446	)	719,183	1.86
Fair value:
Debt securities	$	642		16,926		195,647		505,968

Weighted average yield	3.32		%	2.20	%	1.53	%	1.97	%

Proceeds from sales of available-for-sale investment securities were $166.3 million and $66.5 million for the three months ended March 31, 2014 and 2013, respectively. Gross realized gains and gross realized losses on investment securities for the three months ended March 31, 2014 and 2013 were as follows:



	Three Months Ended
	March 31,
	2014			2013
	(dollars expressed in thousands)
Gross realized gains on sales of available-for-sale securities	$	2,010		346
Gross realized losses on sales of available-for-sale securities	(730		)	(354	)
Other-than-temporary impairment	—			(408	)
Net realized gain (loss) on investment securities	$	1,280		(416	)

Other-than-temporary impairment for the three months ended March 31, 2013 includes impairment of $407,000 recorded during the first quarter of 2013 on a municipal investment security classified as held-to-maturity. Investment securities with a carrying value of $304.8 million and $283.7 million at March 31, 2014 and December 31, 2013, respectively, were pledged in connection with deposits of public and trust funds, securities sold under agreements to repurchase and for other purposes as required by law.

Gross unrealized losses on investment securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at March 31, 2014 and December 31, 2013, were as follows:



	Less Than 12 Months				12 Months or More			Total
	Fair Value		Unrealized Losses		Fair Value	Unrealized Losses		Fair Value	Unrealized Losses
	(dollars expressed in thousands)
March 31, 2014:
Available for sale:
U.S. Government sponsored agencies	$	—	—		14,670	(47	)	14,670	(47	)
Residential mortgage-backed	355,453		(11,046	)	25,617	(1,494	)	381,070	(12,540	)
State and political subdivisions	28,025		(392	)	—	—		28,025	(392	)
Corporate notes	19,826		(173	)	9,574	(426	)	29,400	(599	)
Equity investments	1,691		(59	)	—	—		1,691	(59	)
Total	$	404,995	(11,670	)	49,861	(1,967	)	454,856	(13,637	)
Held to maturity:
U.S. Government sponsored agencies	$	14,238	(135	)	—	—		14,238	(135	)
Residential mortgage-backed	551,649		(10,990	)	84,920	(3,111	)	636,569	(14,101	)
State and political subdivisions	1,041		(82	)	—	—		1,041	(82	)
Total	$	566,928	(11,207	)	84,920	(3,111	)	651,848	(14,318	)

December 31, 2013:
Available for sale:
U.S. Government sponsored agencies	$	16,005	(664	)	—	—		16,005	(664	)
Residential mortgage-backed	511,617		(18,119	)	5,473	(95	)	517,090	(18,214	)
State and political subdivisions	27,872		(560	)	—	—		27,872	(560	)
Corporate notes	9,959		(41	)	4,780	(220	)	14,739	(261	)
Equity investments	1,443		(57	)	—	—		1,443	(57	)
Total	$	566,896	(19,441	)	10,253	(315	)	577,149	(19,756	)
Held to maturity:
U.S. Government sponsored agencies	$	15,966	(153	)	—	—		15,966	(153	)
Residential mortgage-backed	644,700		(20,759	)	10,527	(447	)	655,227	(21,206	)
State and political subdivisions	946		(87	)	—	—		946	(87	)
Total	$	661,612	(20,999	)	10,527	(447	)	672,139	(21,446	)

The Company does not believe the investment securities that were in an unrealized loss position at March 31, 2014 are other-than-temporarily impaired. The unrealized losses on the investment securities were primarily attributable to fluctuations in interest rates. It is expected that the securities would not be settled at a price less than the amortized cost. Because the decline in fair value is attributable to changes in interest rates and not credit loss, and because the Company does not intend to sell these investments and it is more likely than not that First Bank will not be required to sell these securities before the anticipated recovery of the remaining amortized cost basis or maturity, these investments are not considered other-than-temporarily impaired. The unrealized losses for investment securities for 12 months or more at March 31, 2014 and December 31, 2013 included 19 and 12 securities, respectively.