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	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	$ 4,387,598	$ 3,502,915	$ 3,259,845
Equity securities with readily determinable fair value	119,777	139,268	111,943
Loans held-for-investment	144,365		207,532
MSRs	201,044	192,456	224,470	$ 230,225
U.S. Treasury
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	61,175	6,968	4,948
U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	45,715	45,124	74,862
Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	140,590	140,958	160,386
Measured at fair value on a recurring basis:
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account securities	2,184	4,707	102
Equity securities with readily determinable fair value	119,777	139,268	111,943
Mortgage loans held-for-sale	339,884	292,722	302,493
Loans held-for-investment	144,371	155,261	202,143
MSRs	201,044	192,456	224,470
Nonqualified deferred compensation assets	15,953	15,238	14,379
Derivative assets	259,264	275,726	274,004
Total	5,470,075	4,578,293	4,389,379
Derivative liabilities	324,364	267,255	274,432
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	111,711	131,202	103,877
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	172,886	138,170	108,825
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	2,184	4,707	102
Equity securities with readily determinable fair value	8,066	8,066	8,066
Mortgage loans held-for-sale	306,158	265,887	258,243
Loans held-for-investment	95,054	94,591	132,650
MSRs	0	0	0
Nonqualified deferred compensation assets	15,953	15,238	14,379
Derivative assets	253,052	271,216	268,648
Total	4,918,671	4,069,415	3,824,728
Derivative liabilities	324,364	267,255	274,432
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	33,726	26,835	44,250
Loans held-for-investment	49,317	60,670	69,493
MSRs	201,044	192,456	224,470
Nonqualified deferred compensation assets	0	0	0
Derivative assets	6,212	4,510	5,356
Total	378,518	370,708	455,826
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	61,175	6,968	4,948
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	61,175	6,968	4,948
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	45,715	45,124	74,862
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	45,715	45,124	74,862
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	33,726
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	140,590	140,958	160,386
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	52,371	54,721	48,129
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	88,219	86,237	112,257
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	76,725	76,531	83,675
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	76,725	76,531	83,675
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	4,063,393	3,233,334	2,935,974
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	4,063,393	3,233,334	2,935,974
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