Fair Value Measurement and Fair Value of Financial Instruments - Carrying and Fair Values Estimates per the Fair Value Hierarchy of Financial Instruments on a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Financial assets:
Cash and cash equivalents	$ 4,614,984	$ 3,481,784
Interest-bearing deposits with banks	10,498	139,021
Resale agreements	785,000	792,192
HTM debt securities	2,956,040	3,001,868
Restricted equity securities, at cost	79,811	78,624
Loans held-for-investment, net	51,542,039	47,606,785
Financial liabilities:
Time deposits	18,043,464
Repurchase agreements	0	300,000
Carrying Amount
Financial assets:
Cash and cash equivalents	4,614,984	3,481,784
Interest-bearing deposits with banks	10,498	139,021
Resale agreements	785,000	792,192
HTM debt securities	2,956,040	3,001,868
Restricted equity securities, at cost	79,811	78,624
Loans held-for-sale	116	25,644
Loans held-for-investment, net	51,542,039	47,606,785
Mortgage servicing rights	6,602	6,235
Accrued interest receivable	331,490	263,430
Financial liabilities:
Demand, checking, savings and money market deposits	38,048,974	42,637,316
Time deposits	18,043,464	13,330,533
Short-term borrowings	4,500,000
Repurchase agreements		300,000
Long-term debt	148,249	147,950
Accrued interest payable	205,430	37,198
Estimated Fair Value
Financial assets:
Cash and cash equivalents	4,614,984	3,481,784
Interest-bearing deposits with banks	10,498	139,021
Resale agreements	699,056	693,656
HTM debt securities	2,453,971	2,455,171
Restricted equity securities, at cost	79,811	78,624
Loans held-for-sale	116	25,644
Loans held-for-investment, net	50,256,565	46,670,690
Mortgage servicing rights	9,470	10,917
Accrued interest receivable	331,490	263,430
Financial liabilities:
Demand, checking, savings and money market deposits	38,048,974	42,637,316
Time deposits	18,004,951	13,228,777
Short-term borrowings	4,500,000
Repurchase agreements		304,097
Long-term debt	150,896	143,483
Accrued interest payable	205,430	37,198
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	4,614,984	3,481,784
Interest-bearing deposits with banks	0	0
Resale agreements	0	0
HTM debt securities	488,551	471,469
Restricted equity securities, at cost	0	0
Loans held-for-sale	0	0
Loans held-for-investment, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	0	0
Financial liabilities:
Demand, checking, savings and money market deposits	0	0
Time deposits	0	0
Short-term borrowings	0
Repurchase agreements		0
Long-term debt	0	0
Accrued interest payable	0	0
Estimated Fair Value | Level 2
Financial assets:
Cash and cash equivalents	0	0
Interest-bearing deposits with banks	10,498	139,021
Resale agreements	699,056	693,656
HTM debt securities	1,965,420	1,983,702
Restricted equity securities, at cost	79,811	78,624
Loans held-for-sale	116	25,644
Loans held-for-investment, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	331,490	263,430
Financial liabilities:
Demand, checking, savings and money market deposits	38,048,974	42,637,316
Time deposits	18,004,951	13,228,777
Short-term borrowings	4,500,000
Repurchase agreements		304,097
Long-term debt	150,896	143,483
Accrued interest payable	205,430	37,198
Estimated Fair Value | Level 3
Financial assets:
Cash and cash equivalents	0	0
Interest-bearing deposits with banks	0	0
Resale agreements	0	0
HTM debt securities	0	0
Restricted equity securities, at cost	0	0
Loans held-for-sale	0	0
Loans held-for-investment, net	50,256,565	46,670,690
Mortgage servicing rights	9,470	10,917
Accrued interest receivable	0	0
Financial liabilities:
Demand, checking, savings and money market deposits	0	0
Time deposits	0	0
Short-term borrowings	0
Repurchase agreements		0
Long-term debt	0	0
Accrued interest payable	$ 0	$ 0