Investment Securities Available for Sale (Tables)

6 Months Ended

Jun. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Amortized cost and fair value of investment securities available for sale

The following table sets forth certain information regarding the amortized cost and fair values of our investment securities available for sale.

	At June 30, 2016
(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Mortgage-backed securities:
Residential	$	138,277	$	1,109	$	(312	)	$	139,074
Commercial	24,271		436		—			24,707
Municipal bonds	326,717		9,120		(36		)	335,801
Collateralized mortgage obligations:
Residential	161,963		1,850		(407		)	163,406
Commercial	114,475		1,713		(89		)	116,099
Corporate debt securities	83,611		2,059		(421		)	85,249
U.S. Treasury securities	26,019		1		—			26,020
	$	875,333	$	16,288	$	(1,265	)	$	890,356

	At December 31, 2015
(in thousands)	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair value
Mortgage-backed securities:
Residential	$	69,342	$	19	$	(1,260	)	$	68,101
Commercial	18,142		14		(305		)	17,851
Municipal bonds	168,722		3,460		(313		)	171,869
Collateralized mortgage obligations:
Residential	86,167		32		(1,702		)	84,497
Commercial	80,190		43		(1,100		)	79,133
Corporate debt securities	81,280		125		(2,669		)	78,736
U.S. Treasury securities	41,047		—		(83		)	40,964
	$	544,890	$	3,693	$	(7,432	)	$	541,151

Investment securities in an unrealized loss position

Investment securities available for sale that were in an unrealized loss position are presented in the following tables based on the length of time the individual securities have been in an unrealized loss position.

	At June 30, 2016
	Less than 12 months					12 months or more					Total
(in thousands)	Gross unrealized losses			Fair value		Gross unrealized losses			Fair value		Gross unrealized losses			Fair value
Mortgage-backed securities:
Residential	$	(31	)	$	2,047	$	(281	)	$	17,584	$	(312	)	$	19,631
Municipal bonds	(29		)	9,814		(7		)	2,218		(36		)	12,032
Collateralized mortgage obligations:
Residential	(107		)	18,875		(300		)	10,331		(407		)	29,206
Commercial	(40		)	14,351		(49		)	3,997		(89		)	18,348
Corporate debt securities	—			—		(421		)	11,119		(421		)	11,119
U.S. Treasury securities	—			25,020		—			—		—			25,020
	$	(207	)	$	70,107	$	(1,058	)	$	45,249	$	(1,265	)	$	115,356

	At December 31, 2015
	Less than 12 months					12 months or more					Total
(in thousands)	Gross unrealized losses			Fair value		Gross unrealized losses			Fair value		Gross unrealized losses			Fair value
Mortgage-backed securities:
Residential	$	(572	)	$	36,477	$	(688	)	$	21,119	$	(1,260	)	$	57,596
Commercial	(305		)	16,072		—			—		(305		)	16,072
Municipal bonds	(211		)	21,302		(101		)	5,839		(312		)	27,141
Collateralized mortgage obligations:
Residential	(673		)	50,490		(1,029		)	26,028		(1,702		)	76,518
Commercial	(986		)	60,812		(115		)	4,348		(1,101		)	65,160
Corporate debt securities	(1,142		)	36,953		(1,527		)	27,405		(2,669		)	64,358
U.S. Treasury securities	(83		)	40,964		—			—		(83		)	40,964
	$	(3,972	)	$	263,070	$	(3,460	)	$	84,739	$	(7,432	)	$	347,809

Computation of weighted average yield using coupon on the fair value

	At June 30, 2016
	Within one year				After one year through five years				After five years through ten years				After ten years				Total
(dollars in thousands)	Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield
Mortgage-backed securities:
Residential	$	—	—	%	$	2	0.33	%	$	2,645	1.57	%	$	136,427	1.76	%	$	139,074	1.76	%
Commercial	—		—		22,885		2.15		1,822		3.01		—		—		24,707		2.21
Municipal bonds	2,232		3.55		10,337		3.06		54,895		2.51		268,337		3.80		335,801		3.57
Collateralized mortgage obligations:
Residential	—		—		—		—		3,037		1.30		160,369		1.78		163,406		1.78
Commercial	—		—		22,537		2.11		53,505		2.48		40,057		1.99		116,099		2.24
Corporate debt securities	—		—		17,464		2.96		30,884		3.33		36,901		4.15		85,249		3.61
U.S. Treasury securities	25,020		0.36		1,000		0.64		—		—		—		—		26,020		0.37
Total available for sale	$	27,252	0.62	%	$	74,225	2.43	%	$	146,788	2.64	%	$	642,091	2.76	%	$	890,356	2.65	%

	At December 31, 2015
	Within one year				After one year through five years				After five years through ten years				After ten years				Total
(dollars in thousands)	Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield		Fair Value		Weighted Average Yield
Mortgage-backed securities:
Residential	$	—	—	%	$	4	0.39	%	$	3,176	1.63	%	$	64,921	1.88	%	$	68,101	1.87	%
Commercial	—		—		—		—		17,851		2.20		—		—		17,851		2.20
Municipal bonds	510		2.09		8,828		3.33		31,806		3.16		130,725		3.99		171,869		3.79
Collateralized mortgage obligations:
Residential	—		—		—		—		153		0.92		84,344		1.74		84,497		1.74
Commercial	—		—		5,354		1.87		56,506		2.29		17,273		1.87		79,133		2.17
Corporate debt securities	—		—		10,413		2.70		38,291		3.20		30,032		3.64		78,736		3.31
U.S. Treasury securities	39,971		0.39		993		0.63		—		—		—		—		40,964		0.40
Total available for sale	$	40,481	0.41	%	$	25,592	2.65	%	$	147,783	2.69	%	$	327,295	2.83	%	$	541,151	2.60	%

Sales of investment securities available for sale

Sales of investment securities available for sale were as follows.

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2016		2015		2016		2015
Proceeds	$	1,706	$	—	$	11,467	$	—
Gross gains	62		—		97		—
Gross losses	$	—	$	—	$	—	$	—

Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block]

The following table summarizes the carrying value of securities pledged as collateral to secure public deposits, borrowings and other purposes as permitted or required by law:

(in thousands)	At June 30, 2016
Federal Home Loan Bank to secure borrowings	$	122,085
Washington and California State to secure public deposits	31,218
Securities pledged to secure derivatives in a liability position	24,585
Other securities pledged	4,985
Total securities pledged as collateral	$	182,873