- Quantitative Information - Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
FG VIEs' liabilities with recourse, at fair value [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Change in unrealized gains/(losses) related to financial instruments held	$ (31)	$ 1
Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Inputs Hedge Cost	0.05%	0.055%
Fair Value Inputs Bank Profit	0.51%	0.072%
Fair Value Inputs Internal Floor	0.30%	0.088%
Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Inputs Hedge Cost	0.31%	0.825%
Fair Value Inputs Bank Profit	2.12%	5.099%
Fair Value Inputs Internal Floor		0.30%
Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value Inputs Hedge Cost	0.11%	0.233%
Fair Value Inputs Bank Profit	0.76%	0.773%
Fair Value Inputs Internal Floor		0.19%
Level 3 [Member] | Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total liabilities carried at fair value	$ (185)	$ (207)
Level 3 [Member] | Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Year 1 loss estimates (as a percent)	0.00%	0.00%
Level 3 [Member] | Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Year 1 loss estimates (as a percent)	46.00%	66.00%
Level 3 [Member] | Valuation, Income Approach [Member] | Credit derivative liabilities, net [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Year 1 loss estimates (as a percent)	1.30%	2.20%
Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total liabilities carried at fair value	$ (469)	$ (619)
Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	2.70%	5.00%
Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	8.40%	10.20%
Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	4.20%	5.60%
Level 3 [Member] | Valuation, Income Approach [Member] | CLO contracts [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Total liabilities carried at fair value	$ (481)
Yield (as a percent)	10.00%
Prepayment rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	0.10%	0.90%
Prepayment rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	18.60%	18.10%
Prepayment rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	8.60%	9.30%
Default rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	1.20%	1.30%
Default rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	24.70%	23.70%
Default rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	4.90%	5.10%
Loss severity [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	40.00%	60.00%
Loss severity [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	100.00%	100.00%
Loss severity [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Financial Guarantee Variable Interest Entities [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	76.10%	79.80%
Assets of consolidated investment vehicles [Member] | Level 3 [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Yield (as a percent)	12.50%
Assets of consolidated investment vehicles [Member] | Discount rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	16.00%
Assets of consolidated investment vehicles [Member] | Discount rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	28.00%
Assets of consolidated investment vehicles [Member] | Discount rate [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Weighted Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	21.00%
Assets of consolidated investment vehicles [Member] | Multiple enterprise/revenue value [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	50.00%
Assets of consolidated investment vehicles [Member] | Multiple enterprise/revenue value [Member] | Level 3 [Member] | Valuation, Income Approach [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Conditional prepayment rate (as a percent)	670.00%