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, 2022	Dec. 31, 2021
Financial assets:
Cash and cash equivalents	$ 3,481,784	$ 3,912,935
Interest-bearing deposits with banks	139,021	736,492
Resale agreements	792,192	2,353,503
HTM debt securities	3,001,868	0
Restricted equity securities, at cost	78,624	77,434
Loans held-for-investment, net	47,606,785	41,152,202
Financial liabilities:
Time deposits	13,330,533
FHLB advances	0	249,331
Repurchase agreements	300,000	300,000
Carrying Amount
Financial assets:
Cash and cash equivalents	3,481,784	3,912,935
Interest-bearing deposits with banks	139,021	736,492
Resale agreements	792,192	2,353,503
HTM debt securities	3,001,868
Restricted equity securities, at cost	78,624	77,434
Loans held-for-sale	25,644	635
Loans held-for-investment, net	47,606,785	41,152,202
Mortgage servicing rights	6,235	5,706
Accrued interest receivable	263,430	159,833
Financial liabilities:
Demand, checking, savings and money market deposits	42,637,316	45,388,550
Time deposits	13,330,533	7,961,982
FHLB advances		249,331
Repurchase agreements	300,000	300,000
Long-term debt	147,950	147,658
Accrued interest payable	37,198	11,435
Estimated Fair Value
Financial assets:
Cash and cash equivalents	3,481,784	3,912,935
Interest-bearing deposits with banks	139,021	736,492
Resale agreements	693,656	2,335,901
HTM debt securities	2,455,171
Restricted equity securities, at cost	78,624	77,434
Loans held-for-sale	25,644	635
Loans held-for-investment, net	46,670,690	41,199,599
Mortgage servicing rights	10,917	9,104
Accrued interest receivable	263,430	159,833
Financial liabilities:
Demand, checking, savings and money market deposits	42,637,316	45,388,550
Time deposits	13,228,777	7,966,116
FHLB advances		250,372
Repurchase agreements	304,097	310,525
Long-term debt	143,483	151,020
Accrued interest payable	37,198	11,435
Estimated Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and cash equivalents	3,481,784	3,912,935
Interest-bearing deposits with banks	0	0
Resale agreements	0	0
HTM debt securities	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
FHLB advances		0
Repurchase agreements	0	0
Long-term debt	0	0
Accrued interest payable	0	0
Estimated Fair Value | Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and cash equivalents	0	0
Interest-bearing deposits with banks	139,021	736,492
Resale agreements	693,656	2,335,901
HTM debt securities	1,983,702
Restricted equity securities, at cost	78,624	77,434
Loans held-for-sale	25,644	635
Loans held-for-investment, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	263,430	159,833
Financial liabilities:
Demand, checking, savings and money market deposits	42,637,316	45,388,550
Time deposits	13,228,777	7,966,116
FHLB advances		250,372
Repurchase agreements	304,097	310,525
Long-term debt	143,483	151,020
Accrued interest payable	37,198	11,435
Estimated Fair Value | Significant Unobservable Inputs (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
Restricted equity securities, at cost	0	0
Loans held-for-sale	0	0
Loans held-for-investment, net	46,670,690	41,199,599
Mortgage servicing rights	10,917	9,104
Accrued interest receivable		0
Financial liabilities:
Demand, checking, savings and money market deposits	0	0
Time deposits	0	0
FHLB advances		0
Repurchase agreements	0	0
Long-term debt	0	0
Accrued interest payable	$ 0	$ 0