Fair Values of Assets and Liabilities - Schedule of Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 3,912,232		$ 3,502,915	$ 3,611,835
Equity securities with readily determinable fair value	125,310		139,268	134,310
Loans held-for-investment	138,038			171,178
MSRs	186,308	$ 204,610	192,456	210,524	$ 200,692	$ 230,225
U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	98,323		6,968	4,931
U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	47,654		45,124	72,430
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	200,212		140,958	168,523
Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	3,472		4,707	1,663
Equity securities with readily determinable fair value	125,310		139,268	134,310
Mortgage loans held-for-sale	461,067		292,722	304,808
Loans held-for-investment	138,038		155,261	171,178
MSRs	186,308		192,456	210,524
Nonqualified deferred compensation assets	16,756		15,238	14,449
Derivative assets	255,662		275,726	323,705
Total	5,098,845		4,578,293	4,772,472
Derivative liabilities	199,339		267,255	458,706
Measured at fair value on a recurring basis: | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	0		0	0
Equity securities with readily determinable fair value	117,244		131,202	126,244
Mortgage loans held-for-sale	0		0	0
Loans held-for-investment	0		0	0
MSRs	0		0	0
Nonqualified deferred compensation assets	0		0	0
Derivative assets	0		0	0
Total	215,567		138,170	131,175
Derivative liabilities	0		0	0
Measured at fair value on a recurring basis: | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	3,472		4,707	1,663
Equity securities with readily determinable fair value	8,066		8,066	8,066
Mortgage loans held-for-sale	402,004		265,887	279,621
Loans held-for-investment	93,263		94,591	113,217
MSRs	0		0	0
Nonqualified deferred compensation assets	16,756		15,238	14,449
Derivative assets	250,520		271,216	321,189
Total	4,452,740		4,069,415	4,231,890
Derivative liabilities	199,339		267,255	458,706
Measured at fair value on a recurring basis: | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	0		0	0
Equity securities with readily determinable fair value	0		0	0
Mortgage loans held-for-sale	59,063		26,835	25,187
Loans held-for-investment	44,775		60,670	57,961
MSRs	186,308		192,456	210,524
Nonqualified deferred compensation assets	0		0	0
Derivative assets	5,142		4,510	2,516
Total	430,538		370,708	409,407
Derivative liabilities	0		0	0
Measured at fair value on a recurring basis: | U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	98,323		6,968	4,931
Measured at fair value on a recurring basis: | U.S. Treasury | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	98,323		6,968	4,931
Measured at fair value on a recurring basis: | U.S. Treasury | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | U.S. Treasury | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	47,654		45,124	72,430
Measured at fair value on a recurring basis: | U.S. government agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | U.S. government agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	47,654		45,124	72,430
Measured at fair value on a recurring basis: | U.S. government agencies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Mortgage loans held-for-sale	59,063
Measured at fair value on a recurring basis: | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	200,212		140,958	168,523
Measured at fair value on a recurring basis: | Municipal securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | Municipal securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	64,962		54,721	55,304
Measured at fair value on a recurring basis: | Municipal securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	135,250		86,237	113,219
Measured at fair value on a recurring basis: | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	80,117		76,531	76,606
Measured at fair value on a recurring basis: | Corporate notes | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | Corporate notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	80,117		76,531	76,606
Measured at fair value on a recurring basis: | Corporate notes | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | Mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	3,485,926		3,233,334	3,289,345
Measured at fair value on a recurring basis: | Mortgage-backed | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0	0
Measured at fair value on a recurring basis: | Mortgage-backed | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	3,485,926		3,233,334	3,289,345
Measured at fair value on a recurring basis: | Mortgage-backed | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 0		$ 0	$ 0