Investment Securities - Held-to-Maturity with Unrecognized Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value
Less than 12 months	$ 377,088	$ 1,560,831
12 months or longer	2,231,704	1,052,753
Total	2,608,792	2,613,584
Unrecognized Losses
Less than 12 months	(28,016)	(280,316)
12 months or longer	(380,544)	(165,370)
Total	(408,560)	(445,686)
U.S. government-sponsored entities and agencies
Fair Value
Less than 12 months	82,080	354,293
12 months or longer	581,543	302,066
Total	663,623	656,359
Unrecognized Losses
Less than 12 months	(7,003)	(110,523)
12 months or longer	(150,223)	(52,287)
Total	(157,226)	(162,810)
Mortgage-backed securities
Fair Value
Less than 12 months	254,788	367,849
12 months or longer	718,698	615,114
Total	973,486	982,963
Unrecognized Losses
Less than 12 months	(18,775)	(42,438)
12 months or longer	(94,644)	(81,416)
Total	(113,419)	(123,854)
States and political subdivisions
Fair Value
Less than 12 months	40,220	838,689
12 months or longer	931,463	135,573
Total	971,683	974,262
Unrecognized Losses
Less than 12 months	(2,238)	(127,355)
12 months or longer	(135,677)	(31,667)
Total	$ (137,915)	$ (159,022)

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.

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