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 HECM Buyouts (Detail)

Fair Value - Summary of HECM Buyouts (Detail) - HECM Buyouts [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Minimum [Member] \| Loss frequency [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	25.00%	25.00%
Minimum [Member] \| Loss severity [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	4.10%	5.10%
Maximum [Member] \| Loss frequency [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	100.00%	100.00%
Maximum [Member] \| Loss severity [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	11.80%	13.30%
Weighted Average [Member] \| Conditional repayment rate [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Conditional repayment rate	41.20%	42.90%
Weighted Average [Member] \| Loss frequency [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	59.90%	54.80%
Weighted Average [Member] \| Loss severity [Member]
Fair Value HECM Buyouts Securitized Nonperforming Mortgage Loans Held For Investment Subject To Nonrecourse Debt Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss severity	6.10%	7.50%
Discount rate	3.60%	4.10%