Investment Securities (Tables)

12 Months Ended

Dec. 31, 2015

Investments, Debt and Equity Securities [Abstract]

Summary of amortized cost and fair value of investment securities

The following table summarizes the amortized cost and estimated fair value of investment securities and presents the related gross unrealized gains and losses:

December 31, 2015
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-Sale:
Obligations of U.S. government sponsored enterprises	$	2,005	$	3	$	—	$	2,008
Residential mortgage-backed securities-GSE	286,057		339		8,289		278,107
Residential mortgage-backed securities-Private	33,235		578		236		33,577
Commercial mortgage-backed securities-GSE	21,980		—		368		21,612
Commercial mortgage-backed securities-Private	17,869		—		294		17,575
Corporate notes	37,669		—		114		37,555
Total available-for-sale	$	398,815	$	920	$	9,301	$	390,434
Held-to-Maturity:
Residential mortgage-backed securities-GSE	120,197		—		2,310		117,887
Residential mortgage-backed securities-Private	17,712		—		298		17,414
Commercial mortgage-backed securities-Private	10,058		—		174		9,884
Total held-to-maturity	$	147,967	$	—	$	2,782	$	145,185
Total investment securities	$	546,782	$	920	$	12,083	$	535,619
December 31, 2014
(dollars in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-Sale:
Obligations of U.S. government sponsored enterprises	$	2,028	$	16	$	—	$	2,044
Residential mortgage-backed securities-GSE	295,300		438		5,593		290,145
Residential mortgage-backed securities-Private	16,455		820		4		17,271
Commercial mortgage-backed securities-GSE	22,377		—		419		21,958
Commercial mortgage-backed securities-Private	10,365		—		150		10,215
Corporate notes	8,399		8		—		8,407
Total available-for-sale	$	354,924	$	1,282	$	6,166	$	350,040
Held-to-Maturity:
Residential mortgage-backed securities-GSE	132,396		116		1,635		130,877
Commercial mortgage-backed securities-Private	10,065		—		67		9,998
Total held-to-maturity	$	142,461	$	116	$	1,702	$	140,875
Total investment securities	$	497,385	$	1,398	$	7,868	$	490,915

Schedule of other investments

These investments recorded at cost are included in Other Assets on the Consolidated Balance Sheets, as follows:

(dollars in thousands)	December 31,
	2015		2014
Federal Home Loan Bank stock	$	5,971	$	4,855
Federal Reserve Bank stock	9,884		4,713
Total other investments	$	15,855	$	9,568

Schedule of gross gains and losses recognized on the 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,
	2015		2014			2013
Proceeds from sales of investment securities	$	—	$	37,239		$	177,826
Gains on sales of investment securities available-for-sale	—		1,392			2,953
Losses on sales of investment securities available-for-sale	—		(418		)	(181		)
Total securities gains, net	$	—	$	974		$	2,772

Schedule of continuous unrealized loss positions

All unrealized losses on investment securities are considered by management to be temporary given the credit quality of 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
December 31, 2015
Available-for-Sale:
Residential mortgage-backed securities-GSE	$	137,998	$	2,560	$	132,148	$	5,729	$	270,146	$	8,289
Residential mortgage-backed securities-Private	26,265		231		636		5		26,901		236
Commercial mortgage-backed securities-GSE	21,612		368		—		—		21,612		368
Corporate Notes	30,523		114		—		—		30,523		114
Commercial mortgage-backed securities-Private	17,575		294		—		—		17,575		294
Total available-for-sale	$	233,973	$	3,567	$	132,784	$	5,734	$	366,757	$	9,301
Held-to-Maturity:
Residential mortgage-backed securities-GSE	$	83,014	$	1,481	$	34,872	$	829	$	117,886	$	2,310
Residential mortgage-backed securities-Private	17,414		298		—		—		17,414		298
Commercial mortgage-backed securities-Private	9,884		174		—		—		9,884		174
Total held-to-maturity	$	110,312	$	1,953	$	34,872	$	829	$	145,184	$	2,782
Total	$	344,285	$	5,520	$	167,656	$	6,563	$	511,941	$	12,083
December 31, 2014
Available-for-Sale:
Residential mortgage-backed securities-GSE	$	—	$	—	$	245,457	$	5,593	$	245,457	$	5,593
Residential mortgage-backed securities-Private	1,154		4		—		—		1,154		4
Commercial mortgage-backed securities-GSE	—		—		21,958		419		21,958		419
Commercial mortgage-backed securities-Private	—		—		10,215		150		10,215		150
Total available-for-sale	$	1,154	$	4	$	277,630	$	6,162	$	278,784	$	6,166
Held-to-Maturity:
Residential mortgage-backed securities-GSE	$	—	$	—	$	112,878	$	1,635	$	112,878	$	1,635
Commercial mortgage-backed securities-Private	—		—		9,998		67		9,998		67
Total held-to-maturity	$	—	$	—	$	122,876	$	1,702	$	122,876	$	1,702
Total	$	1,154	$	4	$	400,506	$	7,864	$	401,660	$	7,868

Schedule of amortized cost and fair value of securities by remaining contractual maturity

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
U.S. government sponsored agencies
Due in one year or less	$	2,005	$	2,008	$	—	$	—
Residential mortgage-backed securities-GSE
Due after five years through 10 years	1,789		1,821		—		—
Due after ten years	284,268		276,286		120,197		117,887
Residential mortgage-backed securities-Private
Due after ten years	33,235		33,577		17,712		17,414
Commercial mortgage-backed securities-GSE
Due after five years through 10 years	21,980		21,612		—		—
Commercial mortgage-backed securities-Private
Due after ten years	17,869		17,575		10,058		9,884
Corporate notes
Due after five years through 10 years	37,669		37,555		—		—
Total	$	398,815	$	390,434	$	147,967	$	145,185