Derivative Instruments - Notional Values and Net Fair Value of Outstanding Contracts (Details) € in Millions, ¥ in Millions, £ in Millions, kr in Millions, R$ in Millions, Kč in Millions, $ in Millions, $ in Millions, $ in Millions, $ in Millions	Mar. 31, 2018 SEK (kr)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CAD ($)	Mar. 31, 2018 AUD ($)	Mar. 31, 2018 JPY (¥)	Mar. 31, 2018 GBP (£)	Mar. 31, 2018 CZK (Kč)	Mar. 31, 2018 EUR (€)	Mar. 31, 2018 BRL (R$)	Mar. 31, 2018 SGD ($)	Dec. 31, 2017 SEK (kr)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2017 AUD ($)	Dec. 31, 2017 JPY (¥)	Dec. 31, 2017 GBP (£)	Dec. 31, 2017 CZK (Kč)	Dec. 31, 2017 EUR (€)	Dec. 31, 2017 BRL (R$)	Dec. 31, 2017 SGD ($)
Derivative [Line Items]
Net fair value of (liability) asset of outstanding contracts | $		$ 0										$ (2)
Foreign Exchange Forward | U.S. dollar
Derivative [Line Items]
Notional balance of outstanding contracts	kr 13		$ 1	$ 48	¥ 250	£ 3	Kč 368	€ 82	R$ 22	$ 3	kr 13		$ 12	$ 55	¥ 151	£ 13	Kč 361	€ 108	R$ 34	$ 4
Foreign Exchange Forward | Euro
Derivative [Line Items]
Notional balance of outstanding contracts | £						£ 5										£ 5