Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis

The tables below summarize financial assets and financial liabilities measured at fair value on a recurring basis as of March 31, 2023 and December 31, 2022, segregated by the level of the valuation inputs within the fair value hierarchy of ASC Topic 820 utilized to measure fair value.

	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
March 31, 2023
Securities available for sale:
U.S. Treasury	$	5,128,096	$	—	$	—	$	5,128,096
Residential mortgage-backed securities	—		7,022,942		—		7,022,942
States and political subdivisions	—		5,788,295		—		5,788,295
Other	—		42,497		—		42,497
Trading account securities:
U.S. Treasury	26,076		—		—		26,076
States and political subdivisions	—		2,659		—		2,659
Derivative assets:
Interest rate swaps, caps and floors	—		77,060		—		77,060
Commodity swaps and options	—		78,623		—		78,623
Foreign currency forward contracts	186		—		—		186
Derivative liabilities:
Interest rate swaps, caps and floors	—		78,186		—		78,186
Commodity swaps and options	—		77,475		—		77,475
Foreign currency forward contracts	176		—		—		176
December 31, 2022
Securities available for sale:
U.S. Treasury	$	5,051,587	$	—	$	—	$	5,051,587
Residential mortgage-backed securities	—		6,376,236		—		6,376,236
States and political subdivisions	—		6,773,355		—		6,773,355
Other	—		42,427		—		42,427
Trading account securities:
U.S. Treasury	25,879		—		—		25,879
States and political subdivisions	—		2,166		—		2,166
Derivative assets:
Interest rate swaps, caps and floors	—		86,793		—		86,793
Commodity swaps and options	—		106,685		—		106,685
Foreign currency forward contracts	11		—		—		11
Derivative liabilities:
Interest rate swaps, caps and floors	—		95,533		—		95,533
Commodity swaps and options	—		105,392		—		105,392
Foreign currency forward contracts	11		—		—		11

Impaired Loans Remeasured And Reported At Fair Value Specific Valuation Allowance Allocation Method Of Underlying Collateral [Table Text Block]

The following table presents collateral dependent loans that were remeasured and reported at fair value through a specific allocation of the allowance for credit losses on loans based upon the fair value of the underlying collateral during the reported periods.

	Three Months Ended March 31, 2023				Three Months Ended March 31, 2022
	Level 2		Level 3		Level 2		Level 3
Carrying value before allocations	$	368	$	6,242	$	2,064	$	5,711
Specific (allocations) reversals of prior allocations	—		(900)		(126)		3,965
Fair value	$	368	$	5,342	$	1,938	$	9,676

Estimated Fair Values of Financial Instruments

The estimated fair values of financial instruments that are reported at amortized cost in our consolidated balance sheets, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value, were as follows:

	March 31, 2023				December 31, 2022
	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Financial assets:
Level 2 inputs:
Cash and cash equivalents	$	9,301,774	$	9,301,774	$	12,028,132	$	12,028,132
Securities held to maturity	3,711,579		3,601,757		2,639,083		2,467,865
Cash surrender value of life insurance policies	190,601		190,601		190,188		190,188
Accrued interest receivable	191,883		191,883		243,682		243,682
Level 3 inputs:
Loans, net	17,254,506		16,763,098		16,927,348		16,343,417
Financial liabilities:
Level 2 inputs:
Deposits	42,184,155		42,158,490		43,954,196		43,920,741
Federal funds purchased	57,450		57,450		51,650		51,650
Repurchase agreements	4,237,444		4,237,444		4,660,641		4,660,641
Junior subordinated deferrable interest debentures	123,083		123,712		123,069		123,712
Subordinated notes	99,374		96,246		99,335		97,014
Accrued interest payable	24,612		24,612		18,444		18,444