Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Realized (gains) losses included in net income, net of premium amortization	$ 0	$ 0
Impaired loans not covered under loss-share agreements	12,939,000	36,990,000
Allowance for credit losses on interest deferred	164,171,000	176,144,000	$ 52,162,000
Net gain (loss) resulting from fair value changes of these mortgage loans	10,354,000	12,057,000	$ 1,286,000
Impaired Loans, Not Covered
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Allowance for credit losses on interest deferred	$ 5,011,000	$ 12,845,000