XML 104 R58.htm IDEA: XBRL DOCUMENT v3.20.4
Summary of Significant Accounting Policies - Additional Information (Detail)
1 Months Ended 12 Months Ended
Dec. 21, 2021
Dec. 31, 2020
USD ($)
Segment
Summary Of Significant Accounting Policies And Other Information [Line Items]    
Number of reportable segments | Segment   1
Securities held for trading | $   $ 0
Held-to-maturity substantial portion of principal outstanding   85.00%
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 morelikely than not that the fair value of a reporting unit is less than its carrying amount, then performing the quantitative impairment test will be unnecessary.​​​​​​​
Excess AMT credit carryforwards refundable rate   50.00%
Scenario, Forecast [Member]    
Summary Of Significant Accounting Policies And Other Information [Line Items]    
Held-to-maturity substantial portion of principal outstanding 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%