Investment Securities (Tables)

3 Months Ended

Mar. 31, 2013

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 investment securities and presents the related gross unrealized gains and losses:

March 31, 2013
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale:
Obligations of:
U.S. government sponsored enterprises	$	2,069	$	38	$	—	$	2,107
Residential mortgage-backed securities-GSE	409,949		1,794		3,279		408,464
Residential mortgage-backed securities-Private	21,992		879		250		22,621
Commercial mortgage backed securities-GSE	23,054		—		658		22,396
Corporate notes	36,567		240		40		36,767
Total	$	493,631	$	2,951	$	4,227	$	492,355
Held to Maturity:
Residential mortgage-backed securities-GSE	73,515		1		271		73,245
Total	$	567,146	$	2,952	$	4,498	$	565,600
December 31, 2012
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available for Sale:
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

Available-for-sale Securities, Continuous Unrealized Loss Position

The following tables show our investments' estimated fair value and gross unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous unrealized loss position, at March 31, 2013 and December 31, 2012. All unrealized losses on investment securities are considered by management to be temporary given the credit ratings on these investment securities or the short duration of the unrealized loss or both.

	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
March 31, 2013
Available for Sale:
Residential mortgage-backed securities-GSE	$	284,396	$	3,279	$	—	$	—	$	284,396	$	3,279
Residential mortgage-backed securities-Private	3,365		217		4,025		33		7,390		250
Commercial mortgage-backed securities-GSE	22,396		658		—		—		22,396		658
Corporate notes	—		—		3,234		40		3,234		40
Total	$	310,157	$	4,154	$	7,259	$	73	$	317,416	$	4,227
Held to Maturity:
Residential mortgage-backed securities-GSE	$	48,036	$	272	$	—	$	—	$	48,036	$	272
December 31, 2012
Obligations of:
Residential mortgage-backed securities-GSE	$	123,489	$	904	$	7,027	$	44	$	130,516	$	948
Residential mortgage-backed securities-Private	6,482		438		1,017		16		7,499		454
Corporate notes	—		—		3,249		17		3,249		17
Total	$	129,971	$	1,342	$	11,293	$	77	$	141,264	$	1,419

Available-for-sale Securities, by Maturity Dates

The aggregate amortized cost and fair value of securities at March 31, 2013, by remaining contractual maturity, are shown in the following table. Actual expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations.

	Available-for-Sale				Held-to-Maturity
(dollars in thousands)	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Due in one year or less	$	16,458	$	16,551	$	—	$	—
Due after one year through five years	18,904		19,089		—		—
Due after five years through 10 years	3,274		3,234		—		—
Due after 10 years	—		—		—		—
Total	38,636		38,874		—		—
Mortgage-backed securities	454,995		453,481		73,515		73,245
Total	$	493,631	$	492,355	$	73,515	$	73,245