Investment Securities (Tables)

3 Months Ended

Mar. 31, 2013

Investment Securities [Abstract]

Amortized cost and estimated fair value of held-to-maturity securities and available-for-sale securities by contractual maturity

	At March 31, 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	$	3,019	$	8	$	—		$	3,027	$	3,026	$	7	$	—		$	3,033
After 1 year to 5 years		66,617		1,488		(33	)		68,072		66,819		1,526		(51	)		68,294
		69,636		1,496		(33	)		71,099		69,845		1,533		(51	)		71,327
Total	$	69,636	$	1,496	$	(33	)	$	71,099	$	69,845	$	1,533	$	(51	)	$	71,327
Securities Available-for-Sale
U.S. treasuries:
After 5 years to 10 years	$	4,962	$	—	$	(26	)	$	4,936	$	4,960	$	—	$	(22	)	$	4,938
		4,962		—		(26	)		4,936		4,960		—		(22	)		4,938
U.S. government corporations and agencies:
Within 1 year		6,507		47		—			6,554		1,517		9		—			1,526
After 1 year to 5 years		142,969		1,139		(45	)		144,063		148,120		1,509		(70	)		149,559
After 5 years to 10 years		20,914		76		(12	)		20,978		20,953		109		(5	)		21,057
		170,390		1,262		(57	)		171,595		170,590		1,627		(75	)		172,142
State and political subdivisions:
Within 1 year		4,603		45		—			4,648		4,607		75		—			4,682
After 1 year to 5 years		4,479		79		—			4,558		4,130		88		(19	)		4,199
After 5 years to 10 years		39,505		1,238		(23	)		40,720		36,499		1,245		(7	)		37,737
Over 10 years		68,511		4,029		(15	)		72,525		70,495		5,055		—			75,550
		117,098		5,391		(38	)		122,451		115,731		6,463		(26	)		122,168
Residential mortgage-backed securities:
After 5 years to 10 years		23,622		794		—			24,416		20,140		777		—			20,917
Over 10 years		60,991		2,642		—			63,633		66,962		2,861		—			69,823
		84,613		3,436		—			88,049		87,102		3,638		—			90,740
Collateralized mortgage obligations:
After 1 year to 5 years		210		4		—			214		41		—		—			41
After 5 years to 10 years		4		—		—			4		626		7		—			633
Over 10 years		23,400		568		(11	)		23,957		25,698		645		(5	)		26,338
		23,614		572		(11	)		24,175		26,365		652		(5	)		27,012
Corporate bonds:
After 1 year to 5 years		4,994		38		—			5,032		4,993		21		—			5,014
After 5 years to 10 years		15,520		—		(152	)		15,368		—		—		—			—
		20,514		38		(152	)		20,400		4,993		21		—			5,014
Money market mutual funds:
Within 1 year		4,444		—		—			4,444		4,878		—		—			4,878
		4,444		—		—			4,444		4,878		—		—			4,878
Equity securities:
No stated maturity		2,233		832		—			3,065		2,279		696		(133	)		2,842
		2,233		832		—			3,065		2,279		696		(133	)		2,842
Total	$	427,868	$	11,531	$	(284	)	$	439,115	$	416,898	$	13,097	$	(261	)	$	429,734

Information related to sales of securities available for sale

	Three Months Ended March 31,
(Dollars in thousands)	2013		2012
Securities available for sale:
Proceeds from sales	$	10,215	$	62,107
Gross realized gains on sales		185		1,154
Gross realized losses on sales		—		896
Tax expense related to net realized gains on sales		65		90

Amount of securities in an unrealized loss position

	At March 31, 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	$	4,936	$	(26	)	$	—	$	—	$	4,936	$	(26	)
U.S. government corporations and agencies		35,879		(57	)		—		—		35,879		(57	)
State and political subdivisions		6,634		(38	)		—		—		6,634		(38	)
Collateralized mortgage obligations		7,273		(11	)		—		—		7,273		(11	)
Corporate bonds		20,357		(185	)		—		—		20,357		(185	)
Total	$	75,079	$	(317	)	$	—	$	—	$	75,079	$	(317	)

	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	)