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

Fair Value - Summary of Commercial Mortgage Fix and Flip Loans (Detail) - Commercial Mortgage Fix and Flip Loans [Member]	12 Months Ended
	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	10.00%
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	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)	11.90%
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	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%