Loans and Leases Held for Investment - Nonaccrual Loans and Leases by Loan Portfolio Segment and Class (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	$ 185,734	$ 159,168	$ 213,480
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	24,435,218	24,831,721
Loans and leases HFI	24,780,347	25,032,679	24,126,527
Financing Receivable, Nonaccrual, Interest Income	19		5
Leased equipment depreciation	5,304	6,202	6,741
Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	24,594,613	24,873,511
Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	154,237	154,676	198,948
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	13,340,828	13,581,261
Loans and leases HFI	13,506,898	13,750,787	13,492,658
Financing Receivable, Nonaccrual, Interest Income	13		5
Real Estate Mortgage | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	13,352,661	13,596,111
Real Estate Construction and Land
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	1,718,717	1,921,087
Loans and leases HFI	1,892,329	1,947,627	2,861,038
Real Estate Construction and Land | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	1,892,329	1,947,627
Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	30,434	3,135	13,540
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	9,030,497	8,974,976
Loans and leases HFI	9,032,987	8,977,206	7,378,799
Financing Receivable, Nonaccrual, Interest Income	6		0
Commercial | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	9,002,553	8,974,071
Consumer
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	1,063	1,357	992
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	345,176	354,397
Loans and leases HFI	348,133	357,059	394,032
Financing Receivable, Nonaccrual, Interest Income	0		0
Consumer | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	347,070	355,702
Finance Receivable Allowance | Consumer
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	1,063		992
Financing Receivable, Nonaccrual, Interest Income	0		0
Commercial | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	87,548	93,334
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	4,041,500	4,257,633
Loans and leases HFI	4,093,386	4,314,637
Financing Receivable, Nonaccrual, No Allowance	87,426		124,277
Commercial | Real Estate Mortgage | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	4,005,838	4,221,303
Commercial | Finance Receivable Allowance | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	122		7,318
Financing Receivable, Nonaccrual, Interest Income	0		0
Commercial | No Finance Receivable Allowance | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	13		5
Other Residential Real Estate | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	53,489	57,984
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,379,605	3,269,634
Loans and leases HFI	3,458,410	3,346,733
Financing Receivable, Nonaccrual, No Allowance	53,358		44,572
Other Residential Real Estate | Real Estate Mortgage | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,404,921	3,288,749
Other Residential Real Estate | Finance Receivable Allowance | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	131		167
Financing Receivable, Nonaccrual, Interest Income	0		0
Other Residential Real Estate | No Finance Receivable Allowance | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	0		0
Multifamily | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	13,200	3,358
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	5,919,723	6,053,994
Loans and leases HFI	5,955,102	6,089,417
Financing Receivable, Nonaccrual, No Allowance	13,200		22,614
Multifamily | Real Estate Mortgage | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	5,941,902	6,086,059
Multifamily | No Finance Receivable Allowance | Real Estate Mortgage
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	0		0
Commercial Real Estate Construction Loan Receivable | Real Estate Construction and Land
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	331,650	379,387
Loans and leases HFI	364,575	379,387
Commercial Real Estate Construction Loan Receivable | Real Estate Construction and Land | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	364,575	379,387
Residential Real Estate Construction Financing Receivable | Real Estate Construction and Land
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	1,387,067	1,541,700
Loans and leases HFI	1,527,754	1,568,240
Residential Real Estate Construction Financing Receivable | Real Estate Construction and Land | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	1,527,754	1,568,240
Venture Capital Loans | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	28,792	625
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	2,321,666	2,222,097
Loans and leases HFI	2,322,261	2,222,097
Venture Capital Loans | Commercial | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	2,293,469	2,221,472
Venture Capital Loans | Finance Receivable Allowance | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	28,792		163
Financing Receivable, Nonaccrual, Interest Income	0		0
Other Commercial
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, No Allowance	466		5,483
Other Commercial | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	1,642	2,510
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,500,002	3,803,011
Loans and leases HFI	3,501,388	3,804,099
Other Commercial | Commercial | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,499,746	3,801,589
Other Commercial | Finance Receivable Allowance | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	1,176		4,254
Financing Receivable, Nonaccrual, Interest Income	0		0
Other Commercial | No Finance Receivable Allowance
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	6		0
Asset Based | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	0	0
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,208,829	2,949,868
Loans and leases HFI	3,209,338	2,951,010
Financing Receivable, Nonaccrual, No Allowance	0		2,297
Asset Based | Commercial | Performing
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Current	3,209,338	$ 2,951,010
Asset Based | Finance Receivable Allowance | Commercial
Financing Receivable, Nonaccrual [Line Items]
Nonaccrual	0		1,343
Financing Receivable, Nonaccrual, Interest Income	0		0
Asset Based | No Finance Receivable Allowance | Commercial
Financing Receivable, Nonaccrual [Line Items]
Financing Receivable, Nonaccrual, Interest Income	$ 0		$ 0