Loans Held for Investment and the Allowance for Credit Losses - Summary of Amortized Cost and Results of Internal Risk Rating Review Performed for Loans Held for Investment Portfolio (Parenthetical) (Details) - Hotel $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($) Loan
Accounts Notes And Loans Receivable [Line Items]
Loan held for sale price | $	$ 86.6
Rating 4
Accounts Notes And Loans Receivable [Line Items]
Number of loan excluded with risk category that was transferred to loans held for sale | Loan	1