Fair Value of Financial Instruments - Summary of Information about Significant Unobservable Inputs Utilized in Company's Nonrecurring Level 3 Fair Value Measurements (Details) $ in Thousands	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 1,368,115	$ 1,291,926
Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	1,368,115	1,291,926
Fair Value, Measurements, Nonrecurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	804	814
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 804	$ 814
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs	0.120
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Minimum | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs	0.02
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Maximum | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs	0.09
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Weighted Average | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs	0.051
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Weighted Average | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs	0.120
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Significant Unobservable Inputs (Level 3) | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 404
Fair Value, Measurements, Nonrecurring | SBA loans—real estate | Significant Unobservable Inputs (Level 3) | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 400
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs		0.120
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Minimum | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs		0.02
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Maximum | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs		0.17
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Weighted Average | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs		0.087
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Weighted Average | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Measurements Inputs		0.120
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Significant Unobservable Inputs (Level 3) | Market approach | Market data comparison
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans		$ 419
Fair Value, Measurements, Nonrecurring | SBA loans—non-real estate | Significant Unobservable Inputs (Level 3) | Income approach - income capitalization | Capitalization rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans		$ 395