Investment Securities (Tables)

3 Months Ended

Mar. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Available-for-sale securities are summarized as follows as of the dates indicated:


	March 31, 2019
	Amortized		Gross		Gross
	cost		unrealized gains		unrealized losses		Fair value
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	134,173	$	1,269	$	(954)	$	134,488
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		625,776		1,675		(13,481)		613,970
Municipal securities		619		—		(9)		610
Other securities		469		—		—		469
Total investment securities available-for-sale	$	761,037	$	2,944	$	(14,444)	$	749,537


	December 31, 2018
	Amortized		Gross		Gross
	cost		unrealized gains		unrealized losses		Fair value
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	147,283	$	1,232	$	(1,873)	$	146,642
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		661,354		1,056		(19,029)		643,381
Municipal securities		619		—		(9)		610
Other securities		469		—		—		469
Total investment securities available-for-sale	$	809,725	$	2,288	$	(20,911)	$	791,102

Summary of unrealized losses for available-for-sale securities

The tables below summarize the available-for-sale securities with unrealized losses as of the dates shown, along with the length of the impairment period:


	March 31, 2019
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	235	$	—	$	86,197	$	(954)	$	86,432	$	(954)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		15,941		(9)		513,936		(13,472)		529,877		(13,481)
Municipal securities		—		—		441		(9)		441		(9)
Total	$	16,176	$	(9)	$	600,574	$	(14,435)	$	616,750	$	(14,444)


	December 31, 2018
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	30,853	$	(392)	$	69,169	$	(1,481)	$	100,022	$	(1,873)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		127,767		(1,150)		454,662		(17,879)		582,429		(19,029)
Municipal securities		441		(9)		—		—		441		(9)
Total	$	159,061	$	(1,551)	$	523,831	$	(19,360)	$	682,892	$	(20,911)

Held-to-maturity Securities

Held-to-maturity investment securities are summarized as follows as of the dates indicated:


	March 31, 2019
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	147,221	$	33	$	(938)	$	146,316
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		74,506		76		(1,291)		73,291
Total investment securities held-to-maturity	$	221,727	$	109	$	(2,229)	$	219,607


	December 31, 2018
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	157,115	$	2	$	(2,705)	$	154,412
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		78,283		—		(1,769)		76,514
Total investment securities held-to-maturity	$	235,398	$	2	$	(4,474)	$	230,926

Summary of unrealized losses for held-to-maturity securities

The tables below summarize the held-to-maturity securities with unrealized losses as of the dates shown, along with the length of the impairment period:


	March 31, 2019
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—	$	—	$	141,907	$	(938)	$	141,907	$	(938)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		—		—		39,410		(1,291)		39,410		(1,291)
Total	$	—	$	—	$	181,317	$	(2,229)	$	181,317	$	(2,229)


	December 31, 2018
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities:
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	26,660	$	(381)	$	126,475	$	(2,324)	$	153,135	$	(2,705)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		35,235		(79)		41,279		(1,690)		76,514		(1,769)
Total	$	61,895	$	(460)	$	167,754	$	(4,014)	$	229,649	$	(4,474)