Securities (Tables)

9 Months Ended

Sep. 30, 2017

Investments, Debt and Equity Securities [Abstract]

Amortized cost and fair value of investments classified as available-for-sale

	September 30, 2017
(Dollar amounts in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Government agencies	$	14,690	$	30	$	(186	)	$	14,534
Mortgage Backed Securities - residential	225,789		3,412		(861		)	228,340
Mortgage Backed Securities - commercial	1		—		—			1
Collateralized mortgage obligations	349,949		1,401		(3,745		)	347,605
State and municipal obligations	224,978		6,682		(408		)	231,252
Collateralized debt obligations	8,815		4,877		—			13,692
TOTAL	$	824,222	$	16,402	$	(5,200	)	$	835,424

	December 31, 2016
(Dollar amounts in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Government agencies	$	13,594	$	32	$	(377	)	$	13,249
Mortgage Backed Securities-residential	261,878		3,200		(4,073		)	261,005
Mortgage Backed Securities-commercial	4		—		—			4
Collateralized mortgage obligations	353,499		1,021		(6,344		)	348,176
State and municipal obligations	217,365		3,954		(2,396		)	218,923
Collateralized debt obligations	9,181		4,411		(1,224		)	12,368
TOTAL	$	855,521	$	12,618	$	(14,414	)	$	853,725

Schedule of contractual maturities of debt securities

Contractual maturities of debt securities at September 30, 2017 were as follows. Securities not due at a single maturity or with no maturity date, primarily mortgage-backed and equity securities are shown separately.

	Available-for-Sale
	Amortized		Fair
(Dollar amounts in thousands)	Cost		Value
Due in one year or less	$	5,342	$	5,374
Due after one but within five years	43,735		45,078
Due after five but within ten years	82,145		85,260
Due after ten years	117,261		123,766
	248,483		259,478
Mortgage-backed securities and collateralized mortgage obligations	575,739		575,946
TOTAL	$	824,222	$	835,424

Schedule of gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in continuous unrealized loss position

The following tables show the securities’ gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in continuous unrealized loss position, at September 30, 2017 and December 31, 2016. 

	September 30, 2017
	Less Than 12 Months					More Than 12 Months					Total
			Unrealized					Unrealized					Unrealized
(Dollar amounts in thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
U.S. Government agencies	$	13,691	$	(186	)	$	—	$	—		$	13,691	$	(186	)
Mortgage Backed Securities - Residential	$	60,513	$	(806	)	$	3,698	$	(55	)	$	64,211	$	(861	)
Collateralized mortgage obligations	128,330		(1,541		)	72,731		(2,204		)	201,061		(3,745		)
State and municipal obligations	14,422		(123		)	11,356		(285		)	25,778		(408		)
Total temporarily impaired securities	$	216,956	$	(2,656	)	$	87,785	$	(2,544	)	$	304,741	$	(5,200	)

	December 31, 2016
	Less Than 12 Months					More Than 12 Months					Total
			Unrealized					Unrealized					Unrealized
(Dollar amounts in thousands)	Fair Value		Losses			Fair Value		Losses			Fair Value		Losses
US Government entity mortgage-backed securities	$	12,224	$	(377	)	$	—	$	—		$	12,224	$	(377	)
Mortgage Backed Securities - Residential	$	202,248	$	(4,072	)	$	152	$	(1	)	$	202,400	$	(4,073	)
Collateralized mortgage obligations	169,717		(3,086		)	79,999		(3,258		)	249,716		(6,344		)
State and municipal obligations	72,852		(2,396		)	—		—			72,852		(2,396		)
Collateralized Debt Obligations	7,561		(1,224		)	—		—			7,561		(1,224		)
Total temporarily impaired securities	$	464,602	$	(11,155	)	$	80,151	$	(3,259	)	$	544,753	$	(14,414	)

Rollforward of the credit losses recognized in earnings

The table below presents a rollforward of the credit losses recognized in earnings for the three and nine month periods ended September 30, 2017 and 2016:

	Three Months Ended September 30,				Nine Months Ended September 30,
(Dollar amounts in thousands)	2017		2016		2017			2016
Beginning balance	$	7,132	$	13,974	$	13,974		$	13,995
Increases to the amount related to the credit
Loss for which other-than-temporary was previously recognized	—		—		—			—
Reductions for increases in cash flows collected	—		—					(21		)
Reductions for securities called during the period	—		—		(6,842		)	—
Ending balance	$	7,132	$	13,974	$	7,132		$	13,974