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

Fair Value - Summary of Commercial Mortgage Fix and Flip Loans (Detail) - Commercial Mortgage Fix and Flip Loans [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Maximum [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	10.90%	10.00%
Minimum [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	7.50%	5.70%
Weighted Average [Member] \| Prepayment Rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Prepayment rate (SMM)	11.20%	11.90%
Weighted Average [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	7.60%	5.90%
Weighted Average [Member] \| Loss frequency [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	0.40%	0.40%