Fair Value Disclosures (Tables)

12 Months Ended

Dec. 31, 2022

Fair Value Disclosures [Abstract]

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

The following table summarizes the Company’s available-for-sale securities, loans held-for-sale, and derivatives which are measured at fair value on a recurring basis as of December 31, 2022 and 2021 segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (in thousands):

December 31, 2022	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
U.S. Treasury securities	$	482,549	$	—	$	—	$	482,549
Obligations of state and political subdivisions		—		1,898,611		—		1,898,611
Corporate bonds		—		97,850		—		97,850
Residential mortgage-backed securities		—		2,616,566		—		2,616,566
Commercial mortgage-backed securities		—		374,869		—		374,869
Other securities		3,914		—		—		3,914
Total	$	486,463	$	4,987,896	$	—	$	5,474,359
Loans held-for-sale	$	—	$	10,497	$	—	$	10,497
IRLCs	$	—	$	400	$	—	$	400
Forward mortgage-backed securities traded	$	—	$	85	$	—	$	85

December 31, 2021	Level 1 Inputs		Level 2 Inputs			Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
U.S. Treasury securities	$	126,841	$	—		$	—	$	126,841
Obligations of state and political subdivisions		—		2,753,471			—		2,753,471
Corporate bonds		—		63,868			—		63,868
Residential mortgage-backed securities		—		3,259,449			—		3,259,449
Commercial mortgage-backed securities		—		365,120			—		365,120
Other securities		4,430		—			—		4,430
Total	$	131,271	$	6,441,908		$	—	$	6,573,179
Loans held-for-sale	$	—	$	34,122		$	—	$	34,122
IRLCs	$	—	$	1,279		$	—	$	1,279
Forward mortgage-backed securities traded	$	—	$	(147	)	$	—	$	(147	)

Summary of Loans Held-for-Sale at Fair Value

The following table summarizes the Company’s loans held-for-sale at fair value and the net unrealized gains as of the balance sheet dates shown below (in thousands):

	December 31,
	2022		2021
Unpaid principal balance on loans held-for-sale	$	10,226	$	33,200
Net unrealized gains on loans held-for-sale		271		922
Loans held-for-sale at fair value	$	10,497	$	34,122

Summary of Gain Loss on Sale of Mortgage Loans

The following table summarizes the Company’s gains on sale and fees of mortgage loans for the years ended December 31, 2022, 2021 and 2020 (in thousands):

	Years ended December 31,
	2022			2021			2020
Realized gain on sale and fees on mortgage loans*	$	20,357		$	37,091		$	39,378
Change in fair value on loans held-for-sale and IRLCs		(1,554	)		(5,259	)		5,900
Change in forward mortgage-backed securities trades		232			1,413			(1,406	)
Total gain on sale of mortgage loans	$	19,035		$	33,245		$	43,872

* This includes gain on loans held-for-sale carried under the fair value method and lower of cost or market.

Schedule of Estimated Fair Values and Carrying Values of All Financial Instruments

The estimated fair values and carrying values of all financial instruments under current authoritative guidance at December 31, 2022 and 2021, were as follows (in thousands):

	2022				2021
	Carrying		Estimated		Carrying			Estimated			Fair Value
	Value		Fair Value		Value			Fair Value			Hierarchy
Cash and due from banks	$	293,286	$	293,286	$	205,053		$	205,053		Level 1
Interest-bearing demand deposits in banks		37,392		37,392		323,535			323,535		Level 1
Available-for-sale securities		5,474,359		5,474,359		6,573,179			6,573,179		Levels 1 and 2
Loans held-for-investment, net of allowance for    credit losses		6,366,034		6,372,859		5,325,507			5,335,791		Level 3
Loans held-for-sale		11,965		11,965		37,810			37,844		Level 2
Accrued interest receivable		58,162		58,162		57,169			57,169		Level 2
Deposits with stated maturities		524,666		518,811		461,415			462,312		Level 2
Deposits with no stated maturities		10,480,841		10,480,841		10,105,073			10,105,073		Level 1
Borrowings		642,507		642,507		671,152			671,152		Level 2
Accrued interest payable		1,121		1,121		221			221		Level 2
IRLCs		400		400		1,279			1,279		Level 2
Forward mortgage-backed securities trades		85		85		(147	)		(147	)	Level 2