Financial Instruments Derivative Notional Amounts (Details) € in Millions, kr in Millions, SFr in Millions, $ in Millions	Mar. 31, 2021 USD ($)	Mar. 31, 2021 EUR (€)	Mar. 31, 2021 DKK (kr)	Mar. 31, 2021 CHF (SFr)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 DKK (kr)	Dec. 31, 2020 CHF (SFr)
Cross-currency interest rate swap contracts
Derivative [Line Items]
Derivative notional amount	$ 150	€ 650	kr 600	SFr 25	$ 150	€ 650	kr 600	SFr 25
Derivatives Not Designated as Hedging Instruments | Foreign currency forward-exchange contracts
Derivative [Line Items]
Derivative notional amount	1,527				1,633
Derivatives Designated as Hedging Instruments: | Forward-starting interest rate swaps
Derivative [Line Items]
Derivative notional amount	$ 550				$ 550