Investment Securities Available-for-Sale (Tables)

6 Months Ended

Jun. 30, 2019

Investments, Debt and Equity Securities [Abstract]

Schedule of amortized cost and estimated fair value of securities available-for-sale

Amortized cost and estimated fair value of securities available-for-sale are summarized as follows:

			Gross		Gross		Estimated
June 30, 2019	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. agency securities	$	225,389	$	940	$	659	$	225,670
Residential mortgage backed securities		440,243		5,186		1,884		443,545
Municipal bonds		67,835		1,503		—		69,338
Corporate bonds		6,502		70		—		6,572
Other equity investments		218		—		—		218
	$	740,187	$	7,699	$	2,543	$	745,343

			Gross		Gross		Estimated
December 31, 2018	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. agency securities	$	260,150	$	228	$	4,033	$	256,345
Residential mortgage backed securities		477,949		1,575		7,293		472,231
Municipal bonds		45,814		439		484		45,769
Corporate bonds		9,503		79		6		9,576
Other equity investments		218		—		—		218
	$	793,634	$	2,321	$	11,816	$	784,139

Schedule of gross unrealized losses and fair value by length of time that the individual available-for-sale securities have been in a continuous unrealized loss position

Gross unrealized losses and fair value by length of time that the individual available-for-sale securities have been in a continuous unrealized loss position are as follows:

			Less than				12Months
			12Months				or Greater				Total
			Estimated				Estimated				Estimated
June 30, 2019	Number of		Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Securities		Value		Losses		Value		Losses		Value		Losses
U. S. agency securities		39	$	26,149	$	50	$	99,252	$	609	$	125,401	$	659
Residential mortgage backed securities		103		4,234		13		174,316		1,871		178,550		1,884
Municipal bonds		2		1,500		—		—		—		1,500		—
		144	$	31,883	$	63	$	273,568	$	2,480	$	305,451	$	2,543


			Less than				12Months
			12Months				or Greater				Total
			Estimated				Estimated				Estimated
December 31, 2018	Number of		Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Securities		Value		Losses		Value		Losses		Value		Losses
U. S. agency securities		58	$	72,679	$	533	$	144,636	$	3,500	$	217,315	$	4,033
Residential mortgage backed securities		151		61,199		527		225,995		6,766		287,194		7,293
Municipal bonds		11		4,299		50		17,041		434		21,340		484
Corporate bonds		1		1,494		6		—		—		1,494		6
		221	$	139,671	$	1,116	$	387,672	$	10,700	$	527,343	$	11,816

Schedule of amortized cost and estimated fair value of investments available-for-sale by contractual maturity

	June 30, 2019				December 31, 2018
	Amortized		Estimated		Amortized		Estimated
(dollars in thousands)	Cost		Fair Value		Cost		Fair Value
U. S. agency securities maturing:
Oneyear or less	$	114,260	$	114,564	$	128,148	$	125,545
Afteroneyear throughfiveyears		103,105		103,042		119,856		118,883
Fiveyears throughtenyears		8,024		8,064		12,146		11,917
Residential mortgage backed securities		440,243		443,545		477,949		472,231
Municipal bonds maturing:
Oneyear or less		6,947		6,977		8,097		8,167
Afteroneyear throughfiveyears		13,426		13,694		15,025		15,081
Fiveyears throughtenyears		46,399		47,468		21,626		21,385
Aftertenyears		1,063		1,199		1,066		1,136
Corporate bonds maturing:
Afteroneyear throughfiveyears		5,002		5,072		8,003		8,076
Aftertenyears		1,500		1,500		1,500		1,500
Other equity investments		218		218		218		218
	$	740,187	$	745,343	$	793,634	$	784,139