Derivative Financial Instruments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of collateral posted for the net assets/liability positions	$ 0	$ 51,050,000
Interest Rate Swaps/Derivatives [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Reclassification from accumulated other comprehensive income (loss) as increase to interest income	$ 3,000