Investment Securities (Tables)

12 Months Ended

Dec. 31, 2012

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale Securities Reconciliation

The following table summarizes the amortized cost and estimated fair value of available-for-sale investment securities and the related gross unrealized gains and losses are presented below:

(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
December 31, 2012
Obligations of:
U.S. Treasury and government agencies	$	6,646	$	335	$	—	$	6,981
U.S. government sponsored enterprises	22,118		55		—		22,173
States and political subdivisions	5,918		120		—		6,038
Residential mortgage-backed securities-GSE	436,344		5,678		948		441,074
Residential mortgage-backed securities-Private	22,649		750		454		22,945
Commercial mortgage-backed securities-GSE	23,150		209		—		23,359
Commercial mortgage-backed securities-Private	5,283		34		—		5,317
Corporate notes	36,710		270		17		36,963
Total	$	558,818	$	7,451	$	1,419	$	564,850
December 31, 2011
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Obligations of:
U.S. Treasury and government agencies	$	7,081	$	107	$	—	$	7,188
U.S. government sponsored enterprises	32,479		36		151		32,364
States and political subdivisions	6,075		16		1		6,090
Residential mortgage-backed securities-GSE	348,884		2,611		1,222		350,273
Residential mortgage-backed securities-Private	33,111		73		967		32,217
Corporate notes	3,206		—		32		3,174
Total	$	430,836	$	2,843	$	2,373	$	431,306

Available-for-sale Securities, by Maturity Dates

The amortized cost and estimated fair value of investment securities at December 31, 2012, by contractual maturity, are shown in the accompanying table. Actual maturities may differ from contractual maturities because issuers may have the right to prepay obligations with or without prepayment penalties.

	Available-for-Sale
(dollars in thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	18,716	$	18,852
Due after one year through five years	42,764		43,074
Due after five years through 10 years	3,266		3,249
Due after 10 years	6,646		6,981
Total	71,392		72,156
Mortgage-backed securities	487,426		492,694
Total	$	558,818	$	564,850

Gross Gains and Losses Recognized on Sale of Securities

Gross gains and losses recognized (by specific identification) on the sale of securities are summarized as follows:

(dollars in thousands)	Years Ended December 31,
	2012			2011			2010
Proceeds from sales of investment securities	$	212,609		$	290,491		$	214,181
Gains on sales of investment securities available-for-sale	4,501			7,400			10,722
Losses on sales of investment securities available-for-sale	(380		)	(102		)	(75		)
Total securities gains	$	4,121		$	7,298		$	10,647

Other Cost Method Investments

Other investments are recorded at cost and are included in Other Assets on the Consolidated Balance Sheets and are composed of the following:

(dollars in thousands)	December 31,
	2012		2011
Federal Home Loan Bank stock	$	6,254	$	10,733
Federal Reserve Bank stock	3,087		1,169
Other investments	1		2
Total other investments	$	9,342	$	11,904

Available-for-sale Securities, Continuous Unrealized Loss Position

The following table presents a summary of available-for-sale investment securities that had an unrealized loss at December 31:

	Less than 12 Months				12 Months or More				Total
(dollars in thousands)	Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses
December 31, 2012
Residential mortgage-backed securities-GSE	123,489		904		7,027		44		130,516		948
Residential mortgage-backed securities-Private	7,499		454		—		—		7,499		454
Corporate notes	3,249		17		—		—		3,249		17
Total	$	134,237	$	1,375	$	7,027	$	44	$	141,264	$	1,419
December 31, 2011
Obligations of:
U.S. government sponsored enterprises	$	21,248	$	151	$	—	$	—	$	21,248	$	151
States and political subdivisions	1,907		1		—		—		1,907		1
Residential mortgage-backed securities-GSE	89,730		1,042		16,552		180		106,282		1,222
Residential mortgage-backed securities-Private	21,519		967		—		—		21,519		967
Corporate notes	3,173		32		—		—		3,173		32
Total	$	137,577	$	2,193	$	16,552	$	180	$	154,129	$	2,373