Investment Securities Held-to-Maturity (Tables)

6 Months Ended

Jun. 30, 2019

Text Block [Abstract]

Summary of Held-to-Maturity Securities

	June 30, 2019								December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
	(in thousands)
U.S. Treasury	$	—	$	—	$	—	$	—	$	9,960	$	—	$	2	$	9,958
U.S. Government Sponsored Enterprises		162,870		770		72		163,568		234,228		336		803		233,761
SBA Backed Securities		48,666		288		224		48,730		52,051		—		2,065		49,986
U.S. Government Agency and Sponsored Enterprises Mortgage-Backed Securities		1,967,032		20,946		15,751		1,972,227		1,750,408		2,324		55,016		1,697,716
Total	$	2,178,568	$	22,004	$	16,047	$	2,184,525	$	2,046,647	$	2,660	$	57,886	$	1,991,421

Company's Securities Held-to-Maturity

The following table shows the maturity distribution of the Company’s securities held-to-maturity at June 30, 2019.

	Amortized Cost		Fair Value
	(in thousands)
Within one year	$	39,249	$	39,178
After one but within five years		1,831,793		1,836,959
After five but within ten years		294,940		295,580
More than ten years		12,586		12,808
Total	$	2,178,568	$	2,184,525

Unrealized Market Loss of Securities

The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio June 30, 2019. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for 12 months or less and a continuous loss position for 12 months or longer. There are 4 and 169 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 502 holdings at June 30, 2019.

	June 30, 2019
	Less Than 12 Months				12 Months or Longer				Total
Temporarily Impaired Investments	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(in thousands)
U.S. Treasury	$	—	$	—	$	—	$	—	$	—	$	—
U.S. Government Sponsored Enterprises		—		—		29,914		72		29,914		72
SBA Backed Securities		—		—		25,057		224		25,057		224
U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities		19,919		20		725,439		15,731		745,358		15,751
Total temporarily impaired securities	$	19,919	$	20	$	780,410	$	16,027	$	800,329	$	16,047

The following table shows the temporarily impaired securities of the Company’s held-to-maturity portfolio at December 31, 2018. This table shows the unrealized market loss of securities that have been in a continuous unrealized loss position for less than 12 months and a continuous loss position for 12 months or longer. There are 56 and 315 securities that are temporarily impaired for less than 12 months and for 12 months or longer, respectively, out of a total of 475 holdings at December 31, 2018.

	December 31, 2018
	Less Than 12 Months				12 Months or Longer				Total
Temporarily Impaired Investments	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(in thousands)
U.S. Treasury	$	9,958	$	2	$	—	$	—	$	9,958	$	2
U.S. Government Sponsored Enterprises		9,849		42		69,499		761		79,348		803
SBA Backed Securities		—		—		49,987		2,065		49,987		2,065
U.S. Government Agency and Sponsored Enterprise Mortgage-Backed Securities		188,125		2,032		1,249,689		52,984		1,437,814		55,016
Total temporarily impaired securities	$	207,932	$	2,076	$	1,369,175	$	55,810	$	1,577,107	$	57,886