Fair Value Measurement - Quantitative Information - Assets (Details) - Level 3 - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Valuation, Income Approach | Credit derivative liabilities, net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value	$ (194)	$ (154)
Valuation, Income Approach | Warehouse financing debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value	(25)	(23)
Valuation, Income Approach | Securitized borrowing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value	$ (22)	$ (17)
Minimum | Credit derivative liabilities, net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Hedge cost (as a percent)	0.128%	0.08%
Bank profit (as a percent)	0.577%	0.00%
Minimum | Valuation, Income Approach | Warehouse financing debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	13.80%	12.60%
Maximum | Credit derivative liabilities, net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Hedge cost (as a percent)	0.28%	0.371%
Bank profit (as a percent)	2.60%	1.878%
Maximum | Valuation, Income Approach | Warehouse financing debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	16.30%	16.00%
Weighted Average | Credit derivative liabilities, net
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Hedge cost (as a percent)	0.175%	0.126%
Bank profit (as a percent)	1.216%	0.679%
Weighted Average | Valuation, Income Approach | Warehouse financing debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	14.50%	13.80%
Discount Margin | Valuation, Income Approach | Securitized borrowing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	20.60%	23.90%
Market multiple-enterprise value/revenue | Valuation, Market Approach | Liabilities of CIVs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/revenue		10.50
Market multiple-enterprise value/EBITDA | Minimum | Valuation, Market Approach | Securitized borrowing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	10.00
Market multiple-enterprise value/EBITDA | Maximum | Valuation, Market Approach | Securitized borrowing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	11.00
Market multiple-enterprise value/EBITDA | Weighted Average | Valuation, Market Approach | Securitized borrowing
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	10.67
Obligations of state and political subdivisions | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 48	$ 72
Obligations of state and political subdivisions | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	7.30%	4.40%
Obligations of state and political subdivisions | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	27.10%	24.50%
Obligations of state and political subdivisions | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	10.10%	6.20%
RMBS | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 192	$ 216
RMBS | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	7.00%	3.80%
RMBS | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	10.70%	5.60%
RMBS | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	8.40%	4.50%
RMBS | CPR | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	0.00%	0.00%
RMBS | CPR | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	17.30%	22.70%
RMBS | CPR | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	8.10%	10.40%
RMBS | CDR | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	1.50%	1.40%
RMBS | CDR | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	12.00%	12.00%
RMBS | CDR | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	5.90%	5.90%
RMBS | Loss severity | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	50.00%	50.00%
RMBS | Loss severity | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	125.00%	125.00%
RMBS | Loss severity | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	82.50%	84.90%
Life insurance transactions | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 366	$ 367
Yield (as a percent)	10.00%	5.00%
CLOs | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 414	$ 458
CLOs | Discount Margin | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	2.00%	0.00%
CLOs | Discount Margin | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	4.50%	2.90%
CLOs | Discount Margin | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	3.30%	1.80%
Others | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 26	$ 38
Others | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	7.70%	3.20%
Others | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	12.40%	7.90%
Others | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	12.40%	7.90%
FG VIEs' assets | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 210	$ 260
FG VIEs' assets | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	4.80%	1.40%
FG VIEs' assets | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	10.40%	8.00%
FG VIEs' assets | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	7.10%	4.60%
FG VIEs' assets | CPR | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	0.90%	0.90%
FG VIEs' assets | CPR | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	22.00%	24.50%
FG VIEs' assets | CPR | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	15.40%	13.30%
FG VIEs' assets | CDR | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	1.00%	1.40%
FG VIEs' assets | CDR | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	41.00%	26.90%
FG VIEs' assets | CDR | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	7.50%	7.60%
FG VIEs' assets | Loss severity | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	45.00%	45.00%
FG VIEs' assets | Loss severity | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	100.00%	100.00%
FG VIEs' assets | Loss severity | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate	82.20%	81.60%
Equity securities and warrants | Assets of Consolidated Investment Vehicles | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 297	$ 239
Yield (as a percent)	9.20%	7.70%
Equity securities and warrants | Discount Margin | Assets of Consolidated Investment Vehicles | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	19.00%	14.70%
Equity securities and warrants | Discount Margin | Assets of Consolidated Investment Vehicles | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	25.40%	23.90%
Equity securities and warrants | Discount Margin | Assets of Consolidated Investment Vehicles | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	23.30%	21.60%
Equity securities and warrants | Terminal growth rate | Assets of Consolidated Investment Vehicles | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	4.00%
Equity securities and warrants | Market multiple-enterprise value/revenue | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate		185.00%
Equity securities and warrants | Market multiple-enterprise value/revenue | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/revenue		1.10
Conditional prepayment rate	135.00%
Equity securities and warrants | Market multiple-enterprise value/revenue | Minimum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/revenue	1.00
Conditional prepayment rate	130.00%
Market multiple-price to earnings	500.00%
Equity securities and warrants | Market multiple-enterprise value/revenue | Maximum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/revenue	1.10
Market multiple-price to earnings	600.00%
Equity securities and warrants | Market multiple-enterprise value/revenue | Weighted Average | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/revenue	1.05
Conditional prepayment rate	133.00%
Market multiple-price to earnings	550.00%
Equity securities and warrants | Market multiple-enterprise value/EBITDA | Minimum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	3.00	3.00
Equity securities and warrants | Market multiple-enterprise value/EBITDA | Maximum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	12.00	10.50
Equity securities and warrants | Market multiple-enterprise value/EBITDA | Weighted Average | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	10.36	8.95
Equity securities and warrants | Cost | Assets of Consolidated Investment Vehicles | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	100.00%
Corporate securities | Assets of Consolidated Investment Vehicles | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	16.30%	16.40%
Corporate securities | Discount Margin | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 87	$ 91
Corporate securities | Discount Margin | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	22.20%	14.70%
Corporate securities | Discount Margin | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	24.30%	21.40%
Corporate securities | Discount Margin | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	22.90%	17.80%
Corporate securities | Market multiple-enterprise value/EBITDA | Minimum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	3.00
Corporate securities | Market multiple-enterprise value/EBITDA | Maximum | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	8.00
Corporate securities | Market multiple-enterprise value/EBITDA | Weighted Average | Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Market multiple-enterprise value/EBITDA	4.70
Corporate securities | Cost | Assets of Consolidated Investment Vehicles | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	100.00%
Structured products | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 43
Structured products | Assets of Consolidated Investment Vehicles | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	13.80%
Structured products | Assets of Consolidated Investment Vehicles | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	32.90%
Structured products | Assets of Consolidated Investment Vehicles | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	18.60%
Other | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total assets carried at fair value	$ 35	$ 23
Term (years)	10 years	10 years
Other | Minimum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	6.10%	2.70%
Other | Maximum | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	6.80%	3.30%
Other | Weighted Average | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	6.40%	3.00%