Fair Value Disclosures (Tables)

9 Months Ended

Sep. 30, 2021

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):

September 30, 2021

	Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of states and political subdivisions	$	—	$	2,665,367	$	—	$	2,665,367
Corporate bonds		—		32,984		—		32,984
Residential mortgage-backed securities		—		3,028,149		—		3,028,149
Commercial mortgage-backed securities		—		389,016		—		389,016
Other securities		4,468		—		—		4,468
Total	$	4,468	$	6,115,516	$	—	$	6,119,984
Loans held-for-sale	$	—	$	46,081	$	—	$	46,081
IRLCs	$	—	$	1,701	$	—	$	1,701
Forward mortgage-backed securities trades asset	$	—	$	828	$	—	$	828

September 30, 2020

	Level 1 Inputs		Level 2 Inputs			Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of states and political subdivisions	$	—	$	2,367,489		$	—	$	2,367,489
Residential mortgage-backed securities		—		1,509,054			—		1,509,054
Commercial mortgage-backed securities		—		550,168			—		550,168
Other securities		4,569		—			—		4,569
Total	$	4,569	$	4,426,711		$	—	$	4,431,280
Loans held-for-sale	$	—	$	94,666		$	—	$	94,666
IRLCs	$	—	$	5,967		$	—	$	5,967
Forward mortgage-backed securities trades liability	$	—	$	(872	)	$	—	$	(872	)

December 31, 2020

	Level 1 Inputs		Level 2 Inputs			Level 3 Inputs		Total Fair Value
Available-for-sale investment securities:
Obligations of state and political subdivisions	$	—	$	2,426,876		$	—	$	2,426,876
Residential mortgage-backed securities		—		1,472,280			—		1,472,280
Commercial mortgage-backed securities		—		489,316			—		489,316
Other securities		4,557		—			—		4,557
Total	$	4,557	$	4,388,472		$	—	$	4,393,029
Loans held-for-sale	$	—	$	79,585		$	—	$	79,585
IRLCs	$	—	$	4,618		$	—	$	4,618
Forward mortgage-backed securities trades liability	$	—	$	(1,560	)	$	—	$	(1,560	)

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):

	September 30,				December 31,
	2021		2020		2020
Unpaid principal balance on loans held-for-sale	$	44,784	$	91,091	$	76,602
Net unrealized gains on loans held-for-sale		1,297		3,575		2,983
Loans held-for-sale at fair value	$	46,081	$	94,666	$	79,585

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 and nine-months ended September 30, 2021 and 2020 (in thousand):

	Three-Months ended September 30,					Nine-Months ended September 30,
	2021			2020		2021			2020
Realized gain on sale and fees on mortgage loans*	$	9,050		$	13,494	$	29,245		$	25,676
Change in fair value on loans held-for-sale and IRLCs		(1,466	)		1,508		(4,659	)		7,800
Change in forward mortgage-backed securities trades		1,204			226		2,387			(720	)
Total gain on sale of mortgage loans	$	8,788		$	15,228	$	26,973		$	32,756

* 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 carrying value and the estimated fair value of the Company’s contractual off-balance-sheet unfunded lines of credit, loan commitments and letters of credit, which are generally priced at market at the time of funding, are not material. The estimated fair values and carrying values of all financial instruments under current authoritative guidance were as follows (in thousands).

	September 30,										December 31,
	2021				2020						2020
	Carrying Value		Estimated Fair Value		Carrying Value			Estimated Fair Value			Carrying Value			Estimated Fair Value			Fair Value Hierarchy
Cash and due from banks	$	201,901	$	201,901	$	175,088		$	175,088		$	211,113		$	211,113		Level 1
Interest-bearing demand deposits    in banks		359,241		359,241		58,933			58,933			517,971			517,971		Level 1
Available-for-sale securities		6,119,984		6,119,984		4,431,280			4,431,280			4,393,029			4,393,029		Levels 1 and 2
Loans held-for-investment, net of    allowance for credit losses		5,223,124		5,236,471		5,217,641			5,212,972			5,104,499			5,109,885		Level 3
Loans held-for-sale		47,721		47,748		101,055			101,480			83,969			84,233		Level 2
Accrued interest receivable		43,516		43,516		39,804			39,804			53,433			53,433		Level 2
Deposits with stated maturities		469,867		470,985		469,978			472,193			475,542			477,218		Level 2
Deposits with no stated maturities		9,423,250		9,423,250		7,824,910			7,824,910			8,200,275			8,200,275		Level 1
Borrowings		648,679		648,679		503,163			503,163			430,093			430,093		Level 2
Accrued interest payable		294		294		485			485			377			377		Level 2
IRLCs		1,701		1,701		5,967			5,967			4,618			4,618		Level 2
Forward mortgage-backed securities    trades asset (liability)		828		828		(872	)		(872	)		(1,560	)		(1,560	)	Level 2