Real Estate and Other Investments - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) investment	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Number of real estate investments held for sale \| investment	0
Maximum amount of investment in long-term notes payable	$ 12.1	$ 3.0
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Debt Instrument [Line Items]
Total investments	$ 1,400.0	$ 1,400.0
Maximum \| Investments In Joint Ventures \| Income From and Investment In
Debt Instrument [Line Items]
Percent of fair value	20.00%
Maximum \| Investments In Joint Ventures \| Assets Held
Debt Instrument [Line Items]
Percent of fair value	10.00%
Maximum \| Investments In Joint Ventures \| Income
Debt Instrument [Line Items]
Percent of fair value	10.00%
Maximum \| Investments In Joint Ventures \| Investment
Debt Instrument [Line Items]
Percent of fair value	10.00%
Maximum \| Investments In Joint Ventures \| Total Assets
Debt Instrument [Line Items]
Percent of fair value	3.00%

American National Group Inc 10-Q