Investments (Tables)

3 Months Ended

Mar. 31, 2023

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 March 31, 2023 (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	$	387,158	$	—	$	62	$	(61,886)	$	325,334
Utah Housing Corporation bonds	3,460		—		—		(294)		3,166
U.S. government-sponsored enterprises and Treasuries	1,758,032		—		—		(92,548)		1,665,484
Other securities	339,099		—		334		(22,355)		317,078
Total	$	2,487,749	$	—	$	396	$	(177,083)	$	2,311,062
As of December 31, 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	$	389,067	$	—	$	2	$	(68,705)	$	320,364
Utah Housing Corporation bonds	3,584		—		—		(357)		3,227
U.S. government-sponsored enterprises and Treasuries	1,804,726		—		—		(115,416)		1,689,310
Other securities	356,955		—		33		(27,800)		329,188
Total	$	2,554,332	$	—	$	35	$	(212,278)	$	2,342,089

(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.

Schedule of 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 March 31, 2023:
Mortgage-backed securities	$	(1,138)	$	22,201	$	(60,748)	$	297,543	$	(61,886)	$	319,744
Utah Housing Corporation bonds	—		—		(294)		3,166		(294)		3,166
U.S. government-sponsored enterprises and Treasuries	(4,463)		193,623		(88,085)		1,471,861		(92,548)		1,665,484
Other securities	(8,451)		156,624		(13,904)		128,538		(22,355)		285,162
Total	$	(14,052)	$	372,448	$	(163,031)	$	1,901,108	$	(177,083)	$	2,273,556
As of December 31, 2022:
Mortgage-backed securities	$	(13,956)	$	99,598	$	(54,749)	$	220,576	$	(68,705)	$	320,174
Utah Housing Corporation bonds	(357)		3,227		—		—		(357)		3,227
U.S. government-sponsored enterprises and Treasuries	(28,128)		689,300		(87,288)		1,000,010		(115,416)		1,689,310
Other securities	(15,852)		232,546		(11,948)		92,883		(27,800)		325,429
Total	$	(58,293)	$	1,024,671	$	(153,985)	$	1,313,469	$	(212,278)	$	2,338,140

Schedule of Amortized Cost and Fair Value of Securities by Contractual Maturities

As of March 31, 2023, 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 March 31, 2023 Year of Maturity (dollars in thousands)	Amortized Cost		Estimated Fair Value
2023	$	114,993	$	113,061
2024	698,346		670,601
2025	298,066		286,613
2026	548,319		499,306
2027	98,309		95,902
2038	71		73
2039	718		719
2042	2,528		2,227
2043	4,434		4,055
2044	5,412		5,057
2045	5,443		4,940
2046	7,963		7,165
2047	8,386		7,586
2048	2,056		2,001
2049	16,374		14,836
2050	114,601		93,786
2051	161,035		130,855
2052	56,605		50,153
2053	109,892		100,141
2054	83,670		75,428
2055	98,051		94,030
2058	52,477		52,527
Total	$	2,487,749	$	2,311,062