Insurance (Guarantees Related to Annuity Contracts) (Details) - Variable Annuity Guarantees - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Guaranteed Death Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Total account value (3)	$ 93,250	$ 100,034
Separate account value	88,504	95,430
Net amount at risk	$ 8,746	$ 6,617
Average attained age of contract holders	70 years	69 years
Guaranteed Annuitization Benefits
Net Amount at Risk by Product and Guarantee [Line Items]
Total account value (3)	$ 52,496	$ 57,069
Separate account value	51,401	56,027
Net amount at risk	$ 7,584	$ 4,495
Average attained age of contract holders	70 years	69 years