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

Fair Value - Summary of Fix And Flip Loans (Detail) - Fix And Flip Loans [Member]	12 Months Ended
	Dec. 31, 2020
Minimum [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	6.70%
Maximum [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	10.00%
Weighted Average [Member] \| Prepayment Rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Prepayment rate (SMM)	12.40%
Weighted Average [Member] \| Discount rate [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	7.20%
Weighted Average [Member] \| Loss frequency [Member]
Fair Value Fix And Flip Loans Classified Under Mortgage Loans Held For Sale Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Loss frequency	0.80%