Investment Securities (Tables)

6 Months Ended

Jun. 30, 2020

Investment Securities

Schedule of amortized cost and fair value of securities

	June 30, 2020								December 31, 2019
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury and government agency debt securities	$	94,414	$	504	$	—	$	94,918	$	29,832	$	56	$	—	$	29,888
Government-sponsored enterprises debt securities		—		—		—		—		101,697		19		(277)		101,439
Mortgage-backed securities:
Residential - Government agency		224,764		7,853		—		232,617		290,131		2,224		(1,146)		291,209
Residential - Government-sponsored enterprises		375,118		15,794		—		390,912		395,039		6,126		(1,673)		399,492
Commercial - Government agency		612,811		17,324		(456)		629,679		—		—		—		—
Commercial - Government-sponsored enterprises		312,293		10,703		—		322,996		101,798		555		(634)		101,719
Collateralized mortgage obligations:
Government agency		1,887,701		39,538		(655)		1,926,584		2,390,143		7,483		(16,348)		2,381,278
Government-sponsored enterprises		1,518,332		20,194		(457)		1,538,069		772,023		2,505		(3,909)		770,619
Total available-for-sale securities	$	5,025,433	$	111,910	$	(1,568)	$	5,135,775	$	4,080,663	$	18,968	$	(23,987)	$	4,075,644

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

	June 30, 2020
	Amortized		Fair
(dollars in thousands)	Cost		Value
Due in one year or less	$	—	$	—
Due after one year through five years		30,442		30,941
Due after five years through ten years		—		—
Due after ten years		63,972		63,977
		94,414		94,918
Mortgage-backed securities:
Residential - Government agency		224,764		232,617
Residential - Government-sponsored enterprises		375,118		390,912
Commercial - Government agency		612,811		629,679
Commercial - Government-sponsored enterprises		312,293		322,996
Total mortgage-backed securities		1,524,986		1,576,204
Collateralized mortgage obligations:
Government agency		1,887,701		1,926,584
Government-sponsored enterprises		1,518,332		1,538,069
Total collateralized mortgage obligations		3,406,033		3,464,653
Total available-for-sale securities	$	5,025,433	$	5,135,775

Schedule of gross unrealized losses and fair values of securities in a continuous loss position

	Time in Continuous Loss as of June 30, 2020
	Less Than 12 Months				12 Months or More				Total
	Unrealized				Unrealized				Unrealized
(dollars in thousands)	Losses		Fair Value		Losses		Fair Value		Losses		Fair Value
Mortgage-backed securities:
Commercial - Government agency	$	(456)	$	90,834	$	—	$	—	$	(456)	$	90,834
Collateralized mortgage obligations:
Government agency		(603)		200,395		(52)		9,212		(655)		209,607
Government-sponsored enterprises		(430)		124,283		(27)		8,813		(457)		133,096
Total available-for-sale securities with unrealized losses	$	(1,489)	$	415,512	$	(79)	$	18,025	$	(1,568)	$	433,537

	Time in Continuous Loss as of December 31, 2019
	Less Than 12 Months				12 Months or More				Total
	Unrealized				Unrealized				Unrealized
(dollars in thousands)	Losses		Fair Value		Losses		Fair Value		Losses		Fair Value
Government-sponsored enterprises debt securities	$	(277)	$	49,716	$	—	$	—	$	(277)	$	49,716
Mortgage-backed securities:
Residential - Government agency		—		—		(1,146)		109,614		(1,146)		109,614
Residential - Government-sponsored enterprises		(115)		76,481		(1,558)		109,025		(1,673)		185,506
Commercial - Government-sponsored enterprises		(634)		38,062		—		—		(634)		38,062
Collateralized mortgage obligations:
Government agency		(8,049)		969,762		(8,299)		565,764		(16,348)		1,535,526
Government-sponsored enterprises		(583)		180,785		(3,326)		209,752		(3,909)		390,537
Total available-for-sale securities with unrealized losses	$	(9,658)	$	1,314,806	$	(14,329)	$	994,155	$	(23,987)	$	2,308,961