Derivative Instruments and Hedging Activities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral place with counterparties	$ 4
Noncash collateral placed with counterparties	$ 145	$ 118
Cash collateral received from counterparties		40
Noncash collateral received from counterparties		$ 29