Investment Securities (Tables)

6 Months Ended

Jun. 30, 2013

Investments Debt And Equity Securities [Abstract]

Amortized Cost and Estimated Fair Value of Held-to-Maturity Securities and Available-for-Sale Securities by Contractual Maturity

The following table shows the amortized cost and the estimated fair value of the held-to-maturity securities and available-for-sale securities at June 30, 2013 and December 31, 2012 by contractual maturity within each type:

	At June 30, 2013									At December 31, 2012
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Securities Held-to-Maturity
Corporate bonds:
Within 1 year	$	12,313	$	118	$	—		$	12,431	$	3,026	$	7	$	—		$	3,033
After 1 year to 5 years		57,112		969		(483	)		57,598		66,819		1,526		(51	)		68,294
		69,425		1,087		(483	)		70,029		69,845		1,533		(51	)		71,327
Total	$	69,425	$	1,087	$	(483	)	$	70,029	$	69,845	$	1,533	$	(51	)	$	71,327
Securities Available-for-Sale
U.S. treasuries:
After 5 years to 10 years	$	4,963	$	—	$	(200	)	$	4,763	$	4,960	$	—	$	(22	)	$	4,938
		4,963		—		(200	)		4,763		4,960		—		(22	)		4,938
U.S. government corporations and agencies:
Within 1 year		5,998		51		—			6,049		1,517		9		—			1,526
After 1 year to 5 years		153,254		490		(1,649	)		152,095		148,120		1,509		(70	)		149,559
After 5 years to 10 years		15,885		—		(608	)		15,277		20,953		109		(5	)		21,057
		175,137		541		(2,257	)		173,421		170,590		1,627		(75	)		172,142
State and political subdivisions:
Within 1 year		5,383		34		—			5,417		4,607		75		—			4,682
After 1 year to 5 years		3,925		40		(36	)		3,929		4,130		88		(19	)		4,199
After 5 years to 10 years		41,966		844		(562	)		42,248		36,499		1,245		(7	)		37,737
Over 10 years		66,555		2,098		(313	)		68,340		70,495		5,055		—			75,550
		117,829		3,016		(911	)		119,934		115,731		6,463		(26	)		122,168
Residential mortgage-backed securities:
After 5 years to 10 years		22,236		468		(73	)		22,631		20,140		777		—			20,917
Over 10 years		44,750		617		(75	)		45,292		66,962		2,861		—			69,823
		66,986		1,085		(148	)		67,923		87,102		3,638		—			90,740
Collateralized mortgage obligations:
After 1 year to 5 years		155		3		—			158		41		—		—			41
After 5 years to 10 years		—		—		—			—		626		7		—			633
Over 10 years		10,335		74		(93	)		10,316		25,698		645		(5	)		26,338
		10,490		77		(93	)		10,474		26,365		652		(5	)		27,012
Corporate bonds:
After 1 year to 5 years		10,081		23		(207	)		9,897		4,993		21		—			5,014
After 5 years to 10 years		22,179		—		(1,068	)		21,111		—		—		—			—
		32,260		23		(1,275	)		31,008		4,993		21		—			5,014
Money market mutual funds:
Within 1 year		5,500		—		—			5,500		4,878		—		—			4,878
		5,500		—		—			5,500		4,878		—		—			4,878
Equity securities:
No stated maturity		2,161		867		(16	)		3,012		2,279		696		(133	)		2,842
		2,161		867		(16	)		3,012		2,279		696		(133	)		2,842
Total	$	415,326	$	5,609	$	(4,900	)	$	416,035	$	416,898	$	13,097	$	(261	)	$	429,734

Information Related to Sales of Securities Available-for-Sale

The following table presents information related to sales of securities available-for-sale during the six months ended June 30, 2013 and 2012:

	Six Months Ended June 30,
(Dollars in thousands)	2013		2012
Securities available-for-sale:
Proceeds from sales	$	35,415	$	57,162
Gross realized gains on sales		1,524		1,178
Gross realized losses on sales		—		896
Tax expense related to net realized gains on sales		533		99

Amount of Securities in Unrealized Loss Position

The following table shows the amount of securities that were in an unrealized loss position at June 30, 2013 and December 31, 2012:

	At June 30, 2013
	Less than Twelve Months					Twelve Months or Longer				Total
(Dollars in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. treasuries	$	4,763	$	(200	)	$	—	$	—	$	4,763	$	(200	)
U.S. government corporations and agencies		111,718		(2,257	)		—		—		111,718		(2,257	)
State and political subdivisions		25,144		(911	)		—		—		25,144		(911	)
Residential mortgage-backed securities		25,535		(148	)		—		—		25,535		(148	)
Collateralized mortgage obligations		6,602		(93	)		—		—		6,602		(93	)
Corporate bonds		45,778		(1,758	)		—		—		45,778		(1,758	)
Equity securities		1,064		(16	)		—		—		1,064		(16	)
Total	$	220,604	$	(5,383	)	$	—	$	—	$	220,604	$	(5,383	)

	At December 31, 2012
	Less than Twelve Months					Twelve Months or Longer					Total
(Dollars in thousands)	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. treasuries	$	4,938	$	(22	)	$	—	$	—		$	4,938	$	(22	)
U.S. government corporations and agencies		36,793		(75	)		—		—			36,793		(75	)
State and political subdivisions		4,574		(14	)		480		(12	)		5,054		(26	)
Collateralized mortgage obligations		5,006		(5	)		—		—			5,006		(5	)
Corporate bonds		10,410		(51	)		—		—			10,410		(51	)
Equity securities		976		(133	)		—		—			976		(133	)
Total	$	62,697	$	(300	)	$	480	$	(12	)	$	63,177	$	(312	)