Fair Value of Financial Instruments - Schedule of Quantitative Information for Level 3 Fair Value Measurements (Details) $ in Thousands	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 15,308,998	$ 8,691,019
Recurring | Level 3 | Black-Scholes option pricing model
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants	$ 1,952
Recurring | Level 3 | Black-Scholes option pricing model | Volatility | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.3000
Recurring | Level 3 | Black-Scholes option pricing model | Volatility | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.4125
Recurring | Level 3 | Black-Scholes option pricing model | Volatility | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.3133
Recurring | Level 3 | Black-Scholes option pricing model | Risk free interest rate | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.0016
Recurring | Level 3 | Black-Scholes option pricing model | Risk free interest rate | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.0028
Recurring | Level 3 | Black-Scholes option pricing model | Risk free interest rate | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.2000
Recurring | Level 3 | Black-Scholes option pricing model | Marketability Discount | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.0600
Recurring | Level 3 | Black-Scholes option pricing model | Marketability Discount | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.3300
Recurring | Level 3 | Black-Scholes option pricing model | Marketability Discount | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity warrants, input	0.1367
Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 3,904	2,257
Other real estate owned	260
Total assets	4,164
Nonrecurring | Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	3,904	2,257
Other real estate owned	260
Total assets	4,164
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 322	$ 569
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | CRE non-owner-occupied | Cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 593	$ 408
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Investor loans secured by real estate | SBA secured by real estate | Cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 247	$ 140
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.0700
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1000
Nonrecurring | Level 3 | Fair value of collateral | Business loans secured by real estate | SBA secured by real estate | Cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.0781
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Commercial and industrial
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 312
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Commercial and industrial | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0500
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Commercial and industrial | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0500
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Commercial and industrial | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0500
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Franchise non-real estate secured
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 2,428
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Franchise non-real estate secured | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Franchise non-real estate secured | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | Franchise non-real estate secured | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.1000
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, fair value	$ 2	$ 1,140
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Collateral discount and cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0700
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Collateral discount and cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0700
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Collateral discount and cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input	0.0700
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.0700
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.6300
Nonrecurring | Level 3 | Fair value of collateral | Commercial loans | SBA non-real estate secured | Cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans receivable, input		0.1533
Nonrecurring | Level 3 | Fair value of property
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned	$ 260
Nonrecurring | Level 3 | Fair value of property | Cost to sell | Min
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned, input	0.1000
Nonrecurring | Level 3 | Fair value of property | Cost to sell | Max
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned, input	0.1000
Nonrecurring | Level 3 | Fair value of property | Cost to sell | Weighted Average
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned, input	0.1000