Fair Value Measurements - Narrative (Details)	3 Months Ended			9 Months Ended
	Sep. 30, 2019 USD ($) contract	Sep. 30, 2018 USD ($)	Mar. 31, 2017 USD ($)	Sep. 30, 2019 USD ($) contract	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
(Losses) and gains on derivative financial instruments recognized in other non-operating items (less than)	$ (1,000,000)	$ 1,000,000		$ 1,000,000	$ 1,000,000
Fair value of earn-out liability			$ 14,000,000				$ 14,000,000
Other operating income from earn out liability adjustment			$ 13,000,000
Fair value of contingent consideration	$ 0			$ 0
Foreign exchange swaps | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maturity period of swap contracts				6 months
Foreign exchange swaps | Maturity Beyond Six Months
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of foreign currency derivatives held | contract	0			0
Foreign exchange forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value	$ 216,000,000			$ 216,000,000		$ 103,000,000
Derivative asset	1,000,000			1,000,000		1,000,000
Fair Value Measured at Net Asset Value Per Share
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment	$ 10,000,000			$ 10,000,000		$ 8,000,000		$ 15,000,000