Fair Value Disclosures (Tables)

3 Months Ended

Mar. 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, segregated by the level of the valuation inputs within the fair value hierarchy utilized to measure fair value (dollars in thousands):

March 31, 2022	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
U.S. Treasury securities	$	301,344	$	—	$	—	$	301,344
Obligations of state and political subdivisions		—		2,529,481		—		2,529,481
Corporate bonds		—		64,581		—		64,581
Residential mortgage-backed securities		—		3,265,191		—		3,265,191
Commercial mortgage-backed securities		—		337,678		—		337,678
Other securities		4,220		—		—		4,220
Total	$	305,564	$	6,196,931	$	—	$	6,502,495
Loans held-for-sale	$	—	$	22,382	$	—	$	22,382
IRLCs	$	—	$	276	$	—	$	276
Forward mortgage-backed securities trades	$	—	$	2,103	$	—	$	2,103

March 31, 2021	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of states and political subdivisions	$	—	$	2,517,017	$	—	$	2,517,017
Corporate bonds		—		32,490		—		32,490
Residential mortgage-backed securities		—		2,108,594		—		2,108,594
Commercial mortgage-backed securities		—		447,053		—		447,053
Other securities		4,477		—		—		4,477
Total	$	4,477	$	5,105,154	$	—	$	5,109,631
Loans held-for-sale	$	—	$	61,511	$	—	$	61,511
IRLCs	$	—	$	1,645	$	—	$	1,645
Forward mortgage-backed securities trades	$	—	$	2,806	$	—	$	2,806

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 trades	$	—	$	(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 (dollars in thousands):

	March 31,				December 31,
	2022		2021		2021
Unpaid principal balance on loans held-for-sale	$	22,233	$	60,727	$	33,200
Net unrealized gains on loans held-for-sale		149		784		922
Loans held-for-sale at fair value	$	22,382	$	61,511	$	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 three-months ended March 31, 2022 and 2021 (dollars in thousand):

	Three-Months ended March 31,
	2022			2021
Realized gain on sale and fees on mortgage loans*	$	5,998		$	10,728
Change in fair value on loans held-for-sale and IRLCs		(1,915	)		(5,200	)
Change in forward mortgage-backed securities trades		2,250			4,366
Total gain on sale of mortgage loans	$	6,333		$	9,894

* This includes gains 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 were as follows (dollars in thousands).

	March 31,								December 31,
	2022				2021				2021
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Carrying Value			Estimated Fair Value			Fair Value Hierarchy
Cash and due from banks	$	203,187	$	203,187	$	190,350	$	190,350	$	205,053		$	205,053		Level 1
Interest-bearing demand deposits    in banks		394,566		394,566		893,221		893,221		323,535			323,535		Level 1
Available-for-sale securities		6,502,495		6,502,495		5,109,631		5,109,631		6,573,179			6,573,179		Levels 1 and 2
Loans held-for-investment, net of    allowance for credit losses		5,499,256		5,522,778		5,259,588		5,273,235		5,325,507			5,335,791		Level 3
Loans held-for-sale		27,670		26,985		65,405		65,273		37,810			37,844		Level 2
Accrued interest receivable		48,066		48,066		42,322		42,322		57,169			57,169		Level 2
Deposits with stated maturities		449,130		449,987		483,685		485,193		461,415			462,312		Level 2
Deposits with no stated maturities		10,550,695		10,550,695		8,929,762		8,929,762		10,105,073			10,105,073		Level 1
Borrowings		758,595		758,595		548,604		548,604		671,152			671,152		Level 2
Accrued interest payable		268		268		320		320		221			221		Level 2
IRLCs		276		276		1,645		1,645		1,279			1,279		Level 2
Forward mortgage-backed securities    trades asset (liability)		2,103		2,103		2,806		2,806		(147	)		(147	)	Level 2