Loans and Leases Held for Investment and Credit Quality - Summary of Guaranteed and Unguaranteed Loan and Lease Balance by Asset Quality Indicator (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 7,229,003	$ 6,854,154
Guaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	2,758,540	2,703,995
Unguaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 4,470,463	$ 4,150,159
Percentage Guaranteed
Financing Receivable Recorded Investment [Line Items]
% Guaranteed	38.20%	39.50%
Risk Grades 1 - 4
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 6,724,781	$ 6,429,448
Risk Grades 1 - 4 | Guaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	2,540,259	2,508,229
Risk Grades 1 - 4 | Unguaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 4,184,522	$ 3,921,219
Risk Grades 1 - 4 | Percentage Guaranteed
Financing Receivable Recorded Investment [Line Items]
% Guaranteed	37.80%	39.00%
Risk Grade 5
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 370,848	$ 286,517
Risk Grade 5 | Guaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	126,323	115,573
Risk Grade 5 | Unguaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 244,525	$ 170,944
Risk Grade 5 | Percentage Guaranteed
Financing Receivable Recorded Investment [Line Items]
% Guaranteed	34.10%	40.30%
Risk Grades 6 - 8
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 133,374	$ 138,189
Risk Grades 6 - 8 | Guaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	91,958	80,193
Risk Grades 6 - 8 | Unguaranteed Balance
Financing Receivable Recorded Investment [Line Items]
Total Carried at Amortized Cost	$ 41,416	$ 57,996
Risk Grades 6 - 8 | Percentage Guaranteed
Financing Receivable Recorded Investment [Line Items]
% Guaranteed	68.90%	58.00%