Securities (Tables)

12 Months Ended

Dec. 31, 2012

Investments, Debt and Equity Securities [Abstract]

Summary of Investments

The amortized cost, gross unrealized holding gains, gross unrealized holding losses, and fair value of securities by major security type and class of security at December 31, 2012 and 2011 were as follows:

(Dollars in thousands)
December 31, 2012	Amortized Cost (1)		Unrealized Gains		Unrealized Losses			Fair Value
Securities Available for Sale:
Obligations of U.S. government-sponsored enterprises		$29,458		$2,212		$—			$31,670
Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises	217,136		14,097		—			231,233
States and political subdivisions	68,196		4,424		—			72,620
Trust preferred securities:
Individual name issuers	30,677		—		(5,926		)	24,751
Collateralized debt obligations	4,036		—		(3,193		)	843
Corporate bonds	13,905		476		—			14,381
Total securities available for sale		$363,408		$21,209		($9,119	)		$375,498
Held to Maturity:
Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises		$40,381		$1,039		$—			$41,420
Total securities held to maturity		$40,381		$1,039		$—			$41,420
Total securities		$403,789		$22,248		($9,119	)		$416,918

(Dollars in thousands)
December 31, 2011	Amortized Cost (1)		Unrealized Gains		Unrealized Losses			Fair Value
Securities Available for Sale:
Obligations of U.S. government-sponsored enterprises		$29,429		$3,404		$—			$32,833
Mortgage-backed securities issued by U.S.  government agencies and U.S. government-sponsored enterprises	369,946		19,712		—			389,658
States and political subdivisions	74,040		5,453		—			79,493
Trust preferred securities:
Individual name issuers	30,639		—		(8,243		)	22,396
Collateralized debt obligations	4,256		—		(3,369		)	887
Corporate bonds	13,872		813		(403		)	14,282
Perpetual preferred stocks (2)	1,854		—		(150		)	1,704
Total securities available for sale		$524,036		$29,382		($12,165	)		$541,253
Held to Maturity:
Mortgage-backed securities issued by U.S. government agencies and U.S. government-sponsored enterprises		$52,139		$360		$—			$52,499
Total securities held to maturity		$52,139		$360		$—			$52,499
Total securities		$576,175		$29,742		($12,165	)		$593,752

(1) Net of other-than-temporary impairment losses.

(2) Callable at the discretion of the issuer.

Securities by Contractual Maturity

As of December 31, 2012, the amortized cost of debt securities by maturity is presented below.  Mortgage-backed securities are included based on weighted average maturities, adjusted for anticipated prepayments.  All other securities are included based on contractual maturities.  Actual maturities may differ from amounts presented because certain issuers have the right to call or prepay obligations with or without call or prepayment penalties.  Yields on tax exempt obligations are not computed on a tax equivalent basis.  Included in the securities portfolio at December 31, 2012 were debt securities with an amortized cost balance of $91.9 million and a fair value of $86.3 million that are callable at the discretion of the issuers.  Final maturities of the callable securities range from forty-five months to twenty-five years, with call features ranging from one month to five years.

(Dollars in thousands)	Within 1 Year			1-5 Years			5-10 Years			After 10 Years			Totals
Securities Available for Sale:
Obligations of U.S. government-sponsored enterprises:
Amortized cost		$—			$29,458			$—			$—			$29,458
Weighted average yield	—		%	5.40		%	—		%	—		%	5.40		%
Mortgage-backed securities issued by U.S. government-sponsored enterprises:
Amortized cost	89,039			108,484			16,165			3,448			217,136
Weighted average yield	4.30		%	3.88		%	2.64		%	2.29		%	3.93		%
State and political subdivisions:
Amortized cost	7,525			60,671			—			—			68,196
Weighted average yield	3.84		%	3.91		%	—		%	—		%	3.90		%
Trust preferred securities:
Amortized cost (1)	—			—			—			34,713			34,713
Weighted average yield	—		%	—		%	—		%	1.66		%	1.66		%
Corporate bonds:
Amortized cost	3,202			10,703			—			—			13,905
Weighted average yield	6.30		%	4.65		%	—		%	—		%	5.03		%
Total debt securities available for sale:
Amortized cost		$99,766			$209,316			$16,165			$38,161			$363,408
Weighted average yield	4.33		%	4.14		%	2.64		%	1.72		%	3.87		%
Fair value		$104,044			$215,855			$17,214			$38,385			$375,498
Securities Held to Maturity:
Mortgage-backed securities issued by U.S. government-sponsored enterprises:
Amortized cost		$13,449			$21,574			$4,745			$613			$40,381
Weighted average yield	1.99		%	1.83		%	1.74		%	0.52		%	1.85		%
Fair value		$13,795			$22,129			$4,867			$629			$41,420

(1) Net of other-than-temporary impairment losses recognized in earnings.

Summary of Amounts Related to Sales of Securities

The following is a summary of amounts relating to sales of securities:

(Dollars in thousands)
Years ended December 31,	2012			2011			2010
Proceeds from sales (1)		$46,560			$56,461			$99,097
Gross realized gains (1)		$1,224			$919			$852
Gross realized losses	(1		)	(221		)	(123		)
Net realized gains on securities		$1,223			$698			$729

(1) Includes a contribution of appreciated equity securities to the Corporation’s charitable foundation in 2011.  The cost of the contribution, included in noninterest expenses, amounted to $990 thousand in 2011.  This transaction resulted in a realized security gain of $331 thousand for the same period.

Rollforward of OTTI Recognized in Earnings

The following table presents a roll-forward of the cumulative credit-related impairment losses on debt securities for which a portion of an other-than-temporary impairment was recognized in other comprehensive income:

(Dollars in thousands)
Years ended December 31,	2012		2011		2010
Balance at beginning of period		$3,104		$2,913		$2,496
Credit-related impairment loss on debt securities for which an other-than-temporary impairment was not previously recognized	—		—		—
Additional increases to the amount of credit-related impairment loss on debt securities for which an other-than-temporary impairment was previously recognized	221		191		417
Balance at end of period		$3,325		$3,104		$2,913

Securities in a Continuous Unrealized Loss Position

The following table summarizes temporarily impaired investment securities at December 31, 2012, segregated by length of time the securities have been continuously in an unrealized loss position.

(Dollars in thousands)	Less than 12 Months					12 Months or Longer						Total
December 31, 2012	#	Fair Value		Unrealized Losses		#	Fair Value		Unrealized Losses			#	Fair Value		Unrealized Losses
Trust preferred securities:
Individual name issuers	—		$—		$—	11		$24,751		($5,926	)	11		$24,751		($5,926	)
Collateralized debt obligations	—	—		—		2	843		(3,193		)	2	843		(3,193		)
Total temporarily impaired securities	—		$—		$—	13		$25,594		($9,119	)	13		$25,594		($9,119	)

The following table summarizes temporarily impaired investment securities at December 31, 2011, segregated by length of time the securities have been continuously in an unrealized loss position.

(Dollars in thousands)	Less than 12 Months						12 Months or Longer						Total
December 31, 2011	#	Fair Value		Unrealized Losses			#	Fair Value		Unrealized Losses			#	Fair Value		Unrealized Losses
Trust preferred securities:
Individual name issuers	—	—		—			11	22,396		(8,243		)	11	22,396		(8,243		)
Collateralized debt obligations	—	—		—			2	887		(3,369		)	2	887		(3,369		)
Corporate bonds	3	5,203		(403		)	—	—		—			3	5,203		(403		)
Subtotal, debt securities	3	5,203		(403		)	13	23,283		(11,612		)	16	28,486		(12,015		)
Perpetual preferred stocks	2	1,704		(150		)	—	—		—			2	1,704		(150		)
Total temporarily impaired securities	5		$6,907		($553	)	13		$23,283		($11,612	)	18		$30,190		($12,165	)