Finance of America Companies Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Fair Value - Summary of Non-Agency Reverse Mortgage Loans (Detail)

Fair Value - Summary of Non-Agency Reverse Mortgage Loans (Detail) - Non Agency Reverse Mortgage Loans [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Minimum [Member] \| Loan to value [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loan to value	7.40%	0.10%
Minimum [Member] \| Home price appreciation [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Home price appreciation	3.40%	1.10%
Maximum [Member] \| Loan to value [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loan to value	68.30%	62.10%
Maximum [Member] \| Home price appreciation [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Home price appreciation	9.60%	8.90%
Weighted Average [Member] \| Weighted average remaining life in years [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Weighted-average remaining life in years	7 years 9 months 18 days	8 years
Weighted Average [Member] \| Loan to value [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loan to value	47.90%	44.00%
Weighted Average [Member] \| Conditional repayment rate [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Conditional repayment rate	16.50%	16.80%
Weighted Average [Member] \| Loss severity [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	10.00%	10.00%
Weighted Average [Member] \| Home price appreciation [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Home price appreciation	4.70%	5.50%
Weighted Average [Member] \| Discount rate [Member]
Fair Value Non Agency Reverse Mortgage Loans Classified As Reverse Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	3.40%	3.60%