Investments (Tables)

9 Months Ended

Sep. 30, 2022

Investments, Debt and Equity Securities [Abstract]

Schedule of Amortized Cost and Fair Value of Securities Available-for-Sale

The amortized cost and fair value of securities available for sale are as follows:

As of September 30, 2022 (dollars in thousands)	Amortized Cost		Allowance for credit losses(1)		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-sale:
Mortgage-backed securities	$	394,753	$	—	$	1	$	(71,682)	$	323,072
Utah Housing Corporation bonds	3,584		—		—		(279)		3,305
U.S. government-sponsored enterprises and Treasuries	1,928,886		—		—		(124,239)		1,804,647
Other securities	316,317		—		—		(19,801)		296,516
Total	$	2,643,540	$	—	$	1	$	(216,001)	$	2,427,540
As of December 31, 2021 (dollars in thousands)	Amortized Cost		Allowance for credit losses(1)		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-sale:
Mortgage-backed securities	$	376,313	$	—	$	1,857	$	(7,073)	$	371,097
Utah Housing Corporation bonds	6,943		—		18		—		6,961
U.S. government-sponsored enterprises and Treasuries	1,958,943		—		603		(11,893)		1,947,653
Other securities	193,369		—		439		(1,563)		192,245
Total	$	2,535,568	$	—	$	2,917	$	(20,529)	$	2,517,956

(1) Represents the amount of impairment that has resulted from credit-related factors and that was recognized in the consolidated balance sheets (as a credit loss expense on available-for-sale securities). The amount excludes unrealized losses related to non-credit factors.

Available-for-Sale Securities, Continuous Unrealized Loss Position, Fair Value

The following table summarizes the amount of gross unrealized losses for our available-for-sale securities and the estimated fair value for securities having gross unrealized loss positions, categorized by length of time the securities have been in an unrealized loss position:

(Dollars in thousands)	Less than 12 months				12 months or more				Total
	Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value		Gross Unrealized Losses		Estimated Fair Value
As of September 30, 2022:
Mortgage-backed securities	$	(21,060)	$	126,053	$	(50,622)	$	196,946	$	(71,682)	$	322,999
Utah Housing Corporation bonds	(279)		3,305		—		—		(279)		3,305
U.S. government-sponsored enterprises and Treasuries	(84,320)		1,430,124		(39,919)		374,523		(124,239)		1,804,647
Other securities	(15,459)		264,836		(4,342)		31,680		(19,801)		296,516
Total	$	(121,118)	$	1,824,318	$	(94,883)	$	603,149	$	(216,001)	$	2,427,467
As of December 31, 2021:
Mortgage-backed securities	$	(5,534)	$	261,404	$	(1,540)	$	36,587	$	(7,074)	$	297,991
Utah Housing Corporation bonds	—		—		—		—		—		—
U.S. government-sponsored enterprises and Treasuries	(11,892)		1,199,367		—		—		(11,892)		1,199,367
Other securities	(1,563)		132,884		—		—		(1,563)		132,884
Total	$	(18,989)	$	1,593,655	$	(1,540)	$	36,587	$	(20,529)	$	1,630,242

Amortized Cost and Fair Value of Securities by Contractual Maturities

As of September 30, 2022, the amortized cost and fair value of securities, by contractual maturities, are summarized below. Contractual maturities versus actual maturities may differ due to the effect of prepayments.

As of September 30, 2022 Year of Maturity (dollars in thousands)	Amortized Cost		Estimated Fair Value
2022	$	124,994	$	124,744
2023	162,549		157,988
2024	697,586		660,951
2025	297,572		282,163
2026	548,076		484,902
2027	98,109		93,900
2038	72		73
2039	831		810
2042	2,742		2,347
2043	4,834		4,285
2044	5,597		5,047
2045	5,699		5,002
2046	8,170		7,138
2047	8,718		7,750
2048	2,154		2,050
2049	16,820		14,799
2050	119,167		95,297
2051	165,761		131,838
2052	57,773		49,940
2053	117,467		107,891
2054	92,527		85,057
2055	106,322		103,568
Total	$	2,643,540	$	2,427,540