Finance of America Companies Inc. Annual report pursuant to Section 13 and 15(d)

Fair Value - Summary of Inventory Buyouts (Detail)

Fair Value - Summary of Inventory Buyouts (Detail) - Inventory Buyouts [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Minimum [Member] \| Loss severity [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	3.10%
Maximum [Member] \| Loss severity [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	7.70%
Weighted Average [Member] \| Conditional repayment rate [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Conditional repayment rate	43.20%	44.00%
Weighted Average [Member] \| Loss frequency [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	59.40%	46.90%
Weighted Average [Member] \| Loss severity [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	3.80%	10.50%
Weighted Average [Member] \| Discount rate [Member]
Fair Value Inventory Buyouts Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	4.10%	4.10%