Derivative Instruments - Derivatives and Hedges (Details) - Cash Flow Hedges - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Foreign exchange risk
Derivatives and Hedges
Unrecognized (loss) gain included in Accumulated OCI	$ 10	$ 9	$ (4)
Interest rate risk
Derivatives and Hedges
Unrecognized (loss) gain included in Accumulated OCI			$ (1)
Interest rate risk | Maximum
Derivatives and Hedges
Unrecognized (loss) gain included in Accumulated OCI	$ (1)	$ (1)