Fair Value (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Measured at Fair Value Recurring Basis

The following tables summarize financial assets and financial liabilities measured at fair value on a recurring basis at March 31, 2023 and December 31, 2022, segregated by the level of valuation inputs within the fair value hierarchy utilized to measure fair value ($ in thousands). There were no transfers between fair value levels for the three months ended March 31, 2023 and the year ended December 31, 2022.

	March 31, 2023
	Total		Level 1		Level 2		Level 3
U.S. Treasury securities	$	386,903	$	386,903	$	—	$	—
U.S. Government agency obligations		7,254		—		7,254		—
Obligations of states and political subdivisions		4,907		—		4,907		—
Mortgage-backed securities		1,585,098		—		1,585,098		—
Securities available for sale		1,984,162		386,903		1,597,259		—
LHFS		175,926		—		175,926		—
MSR		127,206		—		—		127,206
Other assets - derivatives		13,447		4,571		7,536		1,340
Other liabilities - derivatives		37,105		403		36,702		—

	December 31, 2022
	Total		Level 1		Level 2		Level 3
U.S. Treasury securities	$	391,513	$	391,513	$	—	$	—
U.S. Government agency obligations		7,766		—		7,766		—
Obligations of states and political subdivisions		4,862		—		4,862		—
Mortgage-backed securities		1,619,941		—		1,619,941		—
Securities available for sale		2,024,082		391,513		1,632,569		—
LHFS		135,226		—		135,226		—
MSR		129,677		—		—		129,677
Other assets - derivatives		8,871		54		8,660		157
Other liabilities - derivatives		45,379		474		44,905		—

Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis

The changes in Level 3 assets measured at fair value on a recurring basis for the three months ended March 31, 2023 and 2022 are summarized as follows ($ in thousands):

	MSR			Other Assets - Derivatives
Balance, January 1, 2023	$	129,677		$	157
Total net (loss) gain included in Mortgage banking, net (1)		(5,117	)		1,288
Additions		2,646			—
Sales		—			(105	)
Balance, March 31, 2023	$	127,206		$	1,340
The amount of total gains (losses) for the period included in earnings    that are attributable to the change in unrealized gains or    losses still held at March 31, 2023	$	(3,972	)	$	531
Balance, January 1, 2022	$	87,687		$	1,859
Total net (loss) gain included in Mortgage banking, net (1)		18,235			(842	)
Additions		5,128			—
Sales		—			(1,537	)
Balance, March 31, 2022	$	111,050		$	(520	)
The amount of total gains (losses) for the period included in    earnings that are attributable to the change in unrealized    gains or losses still held at March 31, 2022	$	22,020		$	(1,341	)

(1)Total net (loss) gain included in Mortgage banking, net relating to the MSR includes changes in fair value due to market changes and due to run-off.

Carrying Amounts and Estimated Fair Values of Financial Instruments

The carrying amounts and estimated fair values of financial instruments at March 31, 2023 and December 31, 2022, are as follows ($ in thousands):

	March 31, 2023				December 31, 2022
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Financial Assets:
Level 2 Inputs:
Cash and short-term investments	$	1,297,144	$	1,297,144	$	738,787	$	738,787
Securities held to maturity		1,474,338		1,406,405		1,494,514		1,406,589
Level 3 Inputs:
Net LHFI		12,374,956		12,211,328		12,083,825		11,850,318
Financial Liabilities:
Level 2 Inputs:
Deposits		14,783,661		14,752,438		14,437,648		14,404,661
Federal funds purchased and securities sold under    repurchase agreements		477,980		477,980		449,331		449,331
Other borrowings		1,485,181		1,485,175		1,050,938		1,050,932
Subordinated notes		123,317		106,875		123,262		113,125
Junior subordinated debt securities		61,856		45,773		61,856		46,392

Fair Value and the Contractual Principal Outstanding of the LHFS

The following table provides information about the fair value and the contractual principal outstanding of LHFS accounted for under the fair value option at March 31, 2023 and December 31, 2022 ($ in thousands):

	March 31, 2023		December 31, 2022
Fair value of LHFS	$	120,530	$	64,421
LHFS contractual principal outstanding		118,665		63,427
Fair value less unpaid principal	$	1,865	$	994