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

Fair Value - Summary of Commercial Mortgage Agricultural Loans (Detail) - Commercial Mortgage Agricultural Loans [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Minimum [Member] \| Prepayment Rate [Member]
Fair Value Agricultural Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Prepayment rate (CPR)	10.00%	0.00%
Maximum [Member] \| Prepayment Rate [Member]
Fair Value Agricultural Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Prepayment rate (CPR)	100.00%	1.00%
Weighted Average [Member] \| Discount rate [Member]
Fair Value Agricultural Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Discount rate	4.70%	6.40%
Weighted Average [Member] \| Prepayment Rate [Member]
Fair Value Agricultural Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Prepayment rate (CPR)	28.30%	0.70%
Weighted Average [Member] \| Default Rate [Member]
Fair Value Agricultural Loans Classified Under Mortgage Loans Held For Investment Measured On Recurring And Nonrecurring Basis Fair Value Measurement [Line Items]
Default rate (CDR)	1.00%	0.40%