Derivative Instruments (Schedule Of Offsetting Assets And Liabilities) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Financial Assets
Derivative Instruments, Gross amount of recognized assets	$ 7,058	$ 4,978
Derivative Instruments, Gross amounts offset	(1,936)	(1,869)
Derivative Instruments, Net amount of assets	5,122	3,109
Derivative Instruments, Cash collateral	(4,391)	(2,976)
Derivative Instruments, Non-cash collateral	(368)	(56)
Derivative Instruments, Net amount	363	77
Embedded Derivative Instruments, Gross amount of recognized assets	2,335	1,082
Embedded Derivative Instruments, Gross amounts offset
Embedded Derivative Instruments, Net amount of assets	2,335	1,082
Embedded Derivative Instruments, Cash collateral
Embedded Derivative Instruments, Non-cash collateral
Embedded Derivative Instruments, Net amount	2,335	1,082
Total, Gross amount of recognized assets	9,393	6,060
Total, Gross amounts offset	(1,936)	(1,869)
Total, Net amount of assets	7,457	4,191
Total, Cash collateral	(4,391)	(2,976)
Total, Non-cash collateral	(368)	(56)
Total, Net amount	2,698	1,159
Financial Liabilities
Derivative Instruments, Gross amount of recognized liabilities	1,082	1,456
Derivative Instruments, Gross amounts offset	(8)	(330)
Derivative Instruments, Net amount of liabilities	1,074	1,126
Derivative Instruments, Cash collateral	(747)	(1,061)
Derivative Instruments, Non-cash collateral
Derivative Instruments, Net amount	327	65
Embedded Derivative Instruments, Gross amount of recognized liabilities	5,417	3,986
Embedded Derivative Instruments, Gross amounts offset
Embedded Derivative Instruments, Net amount of liabilities	5,417	3,986
Embedded Derivative Instruments, Cash collateral
Embedded Derivative Instruments, Non-cash collateral
Embedded Derivative Instruments, Net amount	5,417	3,986
Total, Gross amount of recognized liabilities	6,499	5,442
Total, Gross amounts offset	(8)	(330)
Total, Net amount of liabilities	6,491	5,112
Total, Cash collateral	(747)	(1,061)
Total, Net amount	$ 5,744	$ 4,051