Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 21, 2021	Dec. 31, 2019
Summary Of Significant Accounting Policies And Other Information [Line Items]
Number of reportable segments		1
Securities held for trading		$ 0
Held-to-maturity substantial portion of principal outstanding		85.00%
Loans discontinued delinquency period		90 days
Number of reporting units		1
Goodwill impairment description		Goodwill impairment is evaluated by first assessing qualitative factors (events and circumstances) to determine whether it is more likely than not (meaning a likelihood of more than 50 percent) that the fair value of a reporting unit is less than its carrying amount. If, after considering all relevant events and circumstances, an entity determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test will be unnecessary.
Nonqualified stock options		85.00%
Excess AMT credit carryforwards refundable rate		50.00%
Scenario, Forecast [Member]
Summary Of Significant Accounting Policies And Other Information [Line Items]
Excess AMT credit carryforwards refundable rate	(100.00%)
Minimum [Member]
Summary Of Significant Accounting Policies And Other Information [Line Items]
Class A common stock entitled dividend per share percent in comparison to Class B common stock		200.00%
Class A Common Stock [Member]
Summary Of Significant Accounting Policies And Other Information [Line Items]
Approved stock option plan for purchase of common stock		150,000
Class A Common Stock [Member] | Minimum [Member]
Summary Of Significant Accounting Policies And Other Information [Line Items]
Class A common stock entitled dividend per share percent in comparison to Class B common stock		200.00%