

($ in thousands)	December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
AFS debt securities:
U.S. Treasury securities	$	1,049,238	$	130	$	(16,687)	$	1,032,681
U.S. government agency and U.S. government-sponsored enterprise debt securities	1,333,984		2,697		(34,710)		1,301,971
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities:
Commercial mortgage-backed securities	1,242,043		15,791		(28,854)		1,228,980
Residential mortgage-backed securities	2,968,789		8,629		(49,135)		2,928,283
Municipal securities	519,381		10,065		(6,288)		523,158
Non-agency mortgage-backed securities:
Commercial mortgage-backed securities	498,920		3,000		(5,477)		496,443
Residential mortgage-backed securities	889,937		971		(8,977)		881,931
Corporate debt securities	657,516		8,738		(16,589)		649,665
Foreign government bonds	260,447		767		(3,481)		257,733
Asset-backed securities	74,674		185		(301)		74,558
CLOs	592,250		52		(2,352)		589,950
Total AFS debt securities	$	10,087,179	$	51,025	$	(172,851)	$	9,965,353



($ in thousands)	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
AFS debt securities:
U.S. Treasury securities	$	50,310	$	451	$	—	$	50,761
U.S. government agency and U.S. government-sponsored enterprise debt securities	806,814		8,765		(1,260)		814,319
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities:
Commercial mortgage-backed securities	1,125,174		34,306		(5,710)		1,153,770
Residential mortgage-backed securities	1,634,553		27,952		(1,611)		1,660,894
Municipal securities	382,573		13,588		(88)		396,073
Non-agency mortgage-backed securities:
Commercial mortgage-backed securities	234,965		6,107		(1,230)		239,842
Residential mortgage-backed securities	288,520		1,761		(506)		289,775
Corporate debt securities	406,323		3,493		(3,848)		405,968
Foreign government bonds	183,828		163		(1,460)		182,531
Asset-backed securities	63,463		10		(242)		63,231
CLOs	294,000		—		(6,506)		287,494
Total AFS debt securities	$	5,470,523	$	96,596	$	(22,461)	$	5,544,658

The amortized cost of AFS debt securities excludes accrued interest receivables, which are a component of Other assets on the Consolidated Balance Sheet. The accrued interest receivables for AFS debt securities were $33.1 million and $22.3 million as of December 31, 2021 and 2020, respectively. For the Company’s accounting policy related to AFS debt securities’ accrued interest receivable, see Note 1 — Summary of Significant Accounting Policies — Allowance for Credit Losses on Available-for-Sale Debt Securities to the Consolidated Financial Statements in this Form 10-K.

The following tables present the fair value and the associated gross unrealized losses of the Company’s AFS debt securities, aggregated by investment category and the length of time that the securities have been in a continuous unrealized loss position, as of December 31, 2021 and 2020:



($ in thousands)	December 31, 2021
	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
AFS debt securities:
U.S. Treasury securities	$	935,776	$	(14,689)	$	47,881	$	(1,998)	$	983,657	$	(16,687)
U.S. government agency and U.S. government-sponsored enterprise debt securities	773,647		(18,000)		402,907		(16,710)		1,176,554		(34,710)
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities:
Commercial mortgage-backed securities	440,734		(13,589)		257,745		(15,265)		698,479		(28,854)
Residential mortgage-backed securities	2,138,542		(37,691)		330,522		(11,444)		2,469,064		(49,135)
Municipal securities	177,065		(5,682)		17,003		(606)		194,068		(6,288)
Non-agency mortgage-backed securities:
Commercial mortgage-backed securities	301,925		(4,158)		40,013		(1,319)		341,938		(5,477)
Residential mortgage-backed securities	707,792		(8,966)		6,431		(11)		714,223		(8,977)
Corporate debt securities	183,916		(3,084)		251,494		(13,505)		435,410		(16,589)
Foreign government bonds	27,097		(5)		133,279		(3,476)		160,376		(3,481)
Asset-backed securities	24,885		(301)		—		—		24,885		(301)
CLOs	221,586		(64)		291,712		(2,288)		513,298		(2,352)
Total AFS debt securities	$	5,932,965	$	(106,229)	$	1,778,987	$	(66,622)	$	7,711,952	$	(172,851)



($ in thousands)	December 31, 2020
	Less Than 12 Months				12 Months or More				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
AFS debt securities:
U.S. Treasury securities	$	352,521	$	(1,260)	$	—	$	—	$	352,521	$	(1,260)

U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities:
Commercial mortgage-backed securities	292,596		(5,656)		3,543		(54)		296,139		(5,710)
Residential mortgage-backed securities	342,561		(1,611)		—		—		342,561		(1,611)
Municipal securities	24,529		(88)		—		—		24,529		(88)
Non-agency mortgage-backed securities:
Commercial mortgage-backed securities	58,738		(1,230)		7,920		—		66,658		(1,230)
Residential mortgage-backed securities	90,156		(506)		—		—		90,156		(506)
Corporate debt securities	251,674		(3,645)		9,798		(203)		261,472		(3,848)
Foreign government bonds	106,828		(1,460)		—		—		106,828		(1,460)
Asset-backed securities	—		—		34,104		(242)		34,104		(242)
CLOs	—		—		287,494		(6,506)		287,494		(6,506)
Total AFS debt securities	$	1,519,603	$	(15,456)	$	342,859	$	(7,005)	$	1,862,462	$	(22,461)

As of December 31, 2021, the Company had 431 AFS debt securities in a gross unrealized loss position with no credit impairment, consisting primarily of 180 U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities, 50 U.S. government agency and U.S. government-sponsored agency debt securities, 21 U.S. Treasury securities, and 30 corporate debt securities. In comparison, as of December 31, 2020, the Company had 104 AFS debt securities in a gross unrealized loss position with no credit impairment, consisting primarily of three CLOs, 46 U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities, and 17 corporate debt securities.

Each reporting period, the Company assesses each AFS debt security that is in an unrealized loss position to determine whether the decline in fair value below the amortized cost basis resulted from a credit loss or other factors. For a discussion of the factors and criteria the Company uses in analyzing securities for impairment related to credit losses, see Note 1 — Summary of Significant Accounting Policies — Significant Accounting Policies — Allowance for Credit Losses on Available-for-Sale Debt Securities to the Consolidated Financial Statements in this Form 10-K.

•U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities — The market value decline as of December 31, 2021, was primarily due to interest rate movement. Since these securities (issued by Ginnie Mae, Freddie Mac, and Fannie Mae) are guaranteed or sponsored by agencies of the U.S. government, and the credit profiles are strong (rated Aaa, AA+ and AAA by Moody’s Investors Service (“Moody’s”), Standard & Poor's (“S&P”), and Fitch Ratings (“Fitch”), respectively), the Company expects to receive all contractual cash flows on time.

•U.S. government agency and U.S. government-sponsored agency debt securities — The market value decline as of December 31, 2021, was primarily due to interest rate movement. These securities are guaranteed or issued by entities sponsored by the U.S. government and the credit profiles are strong. The Company expects to receive all contractual cash flows on time. These securities consisted of the debt securities issued by:

•U.S. Treasury securities — The market value decline as of December 31, 2021, was primarily due to interest rate movement. These securities are backed by the full faith of the U.S. government and are rated Aaa, AA+, and AAA by Moody’s, S&P, and Fitch, respectively. The Company expects to receive all contractual cash flows on time.

•Corporate debt securities — The market value decline as of December 31, 2021, was primarily due to interest rate movement and spread widening. Since the credit profiles of these securities are strong (rated BBB- or higher by Moody’s, S&P, Fitch, and Kroll Bond Rating Agency), and the contractual payments from these securities have been and are expected to be received on time, the Company believes that the risk of credit losses on these securities is low.

Overall, the Company believes that the credit support levels of the AFS debt securities are strong and, based on current assessments and macroeconomic forecasts, expects that full contractual cash flows will be received even if near-term credit performance could possibly be impacted by the COVID-19 pandemic, including new and more contagious variants.

As of December 31, 2021, the Company had the intent to hold the AFS debt securities with unrealized losses through the anticipated recovery period and it was more-likely-than-not that the Company will not have to sell these securities before recovery of their amortized cost. The issuers of these securities have not, to the Company’s knowledge, established any cause for default on these securities. As a result, the Company expects to recover the entire amortized cost basis of these securities. Accordingly, there was no allowance for credit losses as of both December 31, 2021 and 2020 against these securities, and there was no provision for credit losses recognized for the years ended December 31, 2021 and 2020. For the year ended December 31, 2019, there was no OTTI credit loss recognized.

The following table presents the contractual maturities of AFS debt securities as of December 31, 2021. Expected maturities will differ from contractual maturities on certain securities as the issuers and borrowers of the underlying collateral may have the right to call or prepay obligations with or without prepayment penalties.



($ in thousands)	Amortized Cost		Fair Value
Due within one year	$	1,482,716	$	1,440,069
Due after one year through five years	1,191,837		1,189,880
Due after five years through ten years	1,413,217		1,408,494
Due after ten years	5,999,409		5,926,910
Total AFS debt securities	$	10,087,179	$	9,965,353