Fair Value Measurement and Fair Value of Financial Instruments - Schedule Of The Carrying And Fair Value Estimates Per The Fair Value Hierarchy Of Financial Instruments Measured On a Nonrecurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financial assets:
Cash and cash equivalents	$ 4,694,194	$ 5,250,742
Interest-bearing deposits with banks	68,200	48,198
Resale agreements	425,000	425,000
HTM debt securities	2,880,682	2,917,413
Restricted equity securities, at cost	152,536	165,259
Loans held-for-investment, net	54,976,252	53,024,585
Financial liabilities:
FHLB advances	3,000,000	3,500,000
Repurchase agreements	53,489	0
Carrying Amount
Financial assets:
Cash and cash equivalents	4,694,194	5,250,742
Interest-bearing deposits with banks	68,200	48,198
Resale agreements	425,000	425,000
HTM debt securities	2,880,682	2,917,413
Restricted equity securities, at cost	152,536	165,259
Loans held-for-sale	19,596
Loans held-for-investment, net	54,976,252	53,024,585
Mortgage servicing rights	4,362	5,234
Accrued interest receivable	315,633	316,392
Financial liabilities:
Demand, checking, savings and money market deposits	41,296,069	39,959,251
Time deposits	25,291,487	23,215,772
Short-term borrowings	9,851
FHLB advances	3,000,000	3,500,000
Repurchase agreements	53,489
Long-term debt	32,239	32,001
Accrued interest payable	56,703	61,950
Estimated Fair Value
Financial assets:
Cash and cash equivalents	4,694,194	5,250,742
Interest-bearing deposits with banks	68,200	48,198
Resale agreements	351,212	329,769
HTM debt securities	2,467,362	2,387,754
Restricted equity securities, at cost	152,536	165,259
Loans held-for-sale	19,596
Loans held-for-investment, net	53,569,366	51,328,254
Mortgage servicing rights	7,601	8,822
Accrued interest receivable	315,633	316,392
Financial liabilities:
Demand, checking, savings and money market deposits	41,296,069	39,959,251
Time deposits	25,287,515	23,225,317
Short-term borrowings	9,851
FHLB advances	3,002,069	3,497,953
Repurchase agreements	53,489
Long-term debt	31,629	31,246
Accrued interest payable	56,703	61,950
Estimated Fair Value | Level 1
Financial assets:
Cash and cash equivalents	4,694,194	5,250,742
Interest-bearing deposits with banks	0	0
Resale agreements	0	0
HTM debt securities	519,800	499,858
Restricted equity securities, at cost	0	0
Loans held-for-sale	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
FHLB advances	0	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	68,200	48,198
Resale agreements	351,212	329,769
HTM debt securities	1,947,562	1,887,896
Restricted equity securities, at cost	152,536	165,259
Loans held-for-sale	19,596
Loans held-for-investment, net	0	0
Mortgage servicing rights	0	0
Accrued interest receivable	315,633	316,392
Financial liabilities:
Demand, checking, savings and money market deposits	41,296,069	39,959,251
Time deposits	25,287,515	23,225,317
Short-term borrowings	9,851
FHLB advances	3,002,069	3,497,953
Repurchase agreements	53,489
Long-term debt	31,629	31,246
Accrued interest payable	56,703	61,950
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
Loans held-for-investment, net	53,569,366	51,328,254
Mortgage servicing rights	7,601	8,822
Accrued interest receivable	0	0
Financial liabilities:
Demand, checking, savings and money market deposits	0	0
Time deposits	0	0
Short-term borrowings	0
FHLB advances	0	0
Repurchase agreements	0
Long-term debt	0	0
Accrued interest payable	$ 0	$ 0