Securities (Tables)

3 Months Ended

Mar. 31, 2016

Investments, Debt and Equity Securities [Abstract]

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

	March 31, 2016
(Dollar amounts in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Government agencies	$	10,570	$	198	$	—		$	10,768
Mortgage Backed Securities - residential	211,720		6,210		(16		)	217,914
Mortgage Backed Securities - commercial	8		—		—			8
Collateralized mortgage obligations	422,269		4,322		(2,384		)	424,207
State and municipal obligations	209,289		8,885		(47		)	218,127
Collateralized debt obligations	9,520		4,186		(554		)	13,152
TOTAL	$	863,376	$	23,801	$	(3,001	)	$	884,176

	December 31, 2015
(Dollar amounts in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
U.S. Government agencies	$	10,670	$	46	$	(23	)	$	10,693
Mortgage Backed Securities-residential	208,705		5,089		(630		)	213,164
Mortgage Backed Securities-commercial	9		—		—			9
Collateralized mortgage obligations	441,500		2,141		(6,007		)	437,634
State and municipal obligations	206,291		8,475		(59		)	214,707
Collateralized debt obligations	9,621		5,254		—			14,875
TOTAL	$	876,796	$	21,005	$	(6,719	)	$	891,082

Schedule of contractual maturities of debt securities

Contractual maturities of debt securities at March 31, 2016 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	$	5,798	$	5,900
Due after one but within five years	54,999		56,698
Due after five but within ten years	92,856		97,877
Due after ten years	75,726		81,572
	229,379		242,047
Mortgage-backed securities and collateralized mortgage obligations	633,997		642,129
TOTAL	$	863,376	$	884,176

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 March 31, 2016 and December 31, 2015. 

	March 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
Mortgage Backed Securities - Residential	$	15,659	$	(16	)	$	—	$	—		$	15,659	$	(16	)
Collateralized mortgage obligations	45,269		(363		)	120,504		(2,021		)	165,773		(2,384		)
State and municipal obligations	5,977		(41		)	407		(6		)	6,384		(47		)
Collateralized Debt Obligations	—		—			8,499		(554		)	8,499		(554		)
Total temporarily impaired securities	$	66,905	$	(420	)	$	129,410	$	(2,581	)	$	196,315	$	(3,001	)

	December 31, 2015
	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	$	9,455	$	(23	)	$	—	$	—		$	9,455	$	(23	)
Mortgage Backed Securities - Residential	$	69,940	$	(428	)	$	11,766	$	(202	)	$	81,706	$	(630	)
Collateralized mortgage obligations	151,484		(1,535		)	139,435		(4,472		)	290,919		(6,007		)
State and municipal obligations	3,547		(16		)	3,045		(43		)	6,592		(59		)
Total temporarily impaired securities	$	234,426	$	(2,002	)	$	154,246	$	(4,717	)	$	388,672	$	(6,719	)

Rollforward of the credit losses recognized in earnings

The table below presents a rollforward of the credit losses recognized in earnings for the three month period ended March 31, 2016 and 2015:

	Three Months Ended March 31,
(Dollar amounts in thousands)	2016		2015
Beginning balance	$	13,995	$	14,050
Increases to the amount related to the credit
Loss for which other-than-temporary was previously recognized	—		—
Reductions for increases in cash flows collected	—		(55		)
Amounts realized for securities sold during the period	—		—
Ending balance	$	13,995	$	13,995