Fair Value of Financial Instruments - Schedule of Estimated Fair Values and Carrying Values of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financial assets:
Net loans held for investment	$ 9,137,242	$ 9,258,457
Interest receivable	53,506	52,715
Carrying amount
Financial assets:
Cash and cash equivalents	870,730	810,932
Investment securities	1,464,682	1,471,973
Net loans held for investment	9,137,242	9,258,457
Loans held for sale, at fair value	61,828	46,618
Interest receivable	53,506	52,715
Mortgage servicing rights	165,674	164,249
Derivatives	38,341	34,738
Financial liabilities:
Without stated maturities	8,902,546	8,927,654
With stated maturities	1,602,382	1,620,633
Securities sold under agreements to repurchase and federal funds purchased	78,229	108,764
Bank Term Funding Program	130,000	130,000
Subordinated debt, net	130,414	129,645
Interest payable	20,504	18,809
Derivatives	36,404	38,215
Fair Value
Financial assets:
Cash and cash equivalents	870,730	810,932
Investment securities	1,464,682	1,471,973
Net loans held for investment	8,809,892	9,068,518
Loans held for sale, at fair value	61,828	46,618
Interest receivable	53,506	52,715
Mortgage servicing rights	165,674	164,249
Derivatives	38,341	34,738
Financial liabilities:
Without stated maturities	8,902,546	8,927,654
With stated maturities	1,594,332	1,614,400
Securities sold under agreements to repurchase and federal funds purchased	78,229	108,764
Bank Term Funding Program	129,462	130,000
Subordinated debt, net	123,284	122,671
Interest payable	20,504	18,809
Derivatives	36,404	38,215
Fair Value | Level 1
Financial assets:
Cash and cash equivalents	870,730	810,932
Investment securities	0	0
Net loans held for investment	0	0
Loans held for sale, at fair value	0	0
Interest receivable	892	388
Mortgage servicing rights	0	0
Derivatives	0	0
Financial liabilities:
Without stated maturities	8,902,546	8,927,654
With stated maturities	0	0
Securities sold under agreements to repurchase and federal funds purchased	78,229	108,764
Bank Term Funding Program	0	0
Subordinated debt, net	0	0
Interest payable	4,187	4,104
Derivatives	0	0
Fair Value | Level 2
Financial assets:
Cash and cash equivalents	0	0
Investment securities	1,464,682	1,471,973
Net loans held for investment	0	0
Loans held for sale, at fair value	61,828	46,618
Interest receivable	6,774	8,551
Mortgage servicing rights	0	0
Derivatives	38,341	34,738
Financial liabilities:
Without stated maturities	0	0
With stated maturities	1,594,332	1,614,400
Securities sold under agreements to repurchase and federal funds purchased	0	0
Bank Term Funding Program	129,462	130,000
Subordinated debt, net	0	0
Interest payable	15,942	13,205
Derivatives	36,404	38,215
Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Investment securities	0	0
Net loans held for investment	8,809,892	9,068,518
Loans held for sale, at fair value	0	0
Interest receivable	45,840	43,776
Mortgage servicing rights	165,674	164,249
Derivatives	0	0
Financial liabilities:
Without stated maturities	0	0
With stated maturities	0	0
Securities sold under agreements to repurchase and federal funds purchased	0	0
Bank Term Funding Program	0	0
Subordinated debt, net	123,284	122,671
Interest payable	375	1,500
Derivatives	$ 0	$ 0