Financial Instruments and Risk Concentration - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) Customer	Dec. 31, 2017 Customer	Dec. 31, 2016 Customer
Customer Concentration Risk | Sales Revenue, Segment
Valuation and Qualifying Accounts Disclosure [Line Items]
Customer accounted for 10% or more of revenue | Customer	0	0	0
Foreign Exchange Forward
Valuation and Qualifying Accounts Disclosure [Line Items]
Notional value of forward foreign currency exchange contracts	$ 525
Foreign Exchange Forward | Japanese Yen
Valuation and Qualifying Accounts Disclosure [Line Items]
Notional value of forward foreign currency exchange contracts	160
Foreign Exchange Forward | Indian Rupees
Valuation and Qualifying Accounts Disclosure [Line Items]
Notional value of forward foreign currency exchange contracts	94
Foreign Exchange Forward | Euros
Valuation and Qualifying Accounts Disclosure [Line Items]
Notional value of forward foreign currency exchange contracts	$ 99