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Derivative Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Derivative Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	$ 995.3		$ 995.3		$ 656.4
Changes in fair value of non-designated derivatives	0.0	$ 0.0	0.0	$ 0.0
Designated as hedge
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	833.4		833.4		497.7
Non-designated derivatives
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	161.9		$ 161.9		158.7
Cash flow hedges \| Designated as hedge
Derivatives, Notional Amount [Line Items]
Maturities of cash flow hedge derivatives			18 months
Losses expected to be reclassified into earnings within the next 12 months			$ 8.8
Foreign exchange contracts \| Cash flow hedges
Derivatives, Notional Amount [Line Items]
Derivative instruments, gain (loss) recognized in other comprehensive income (loss), Effective portion	(12.4)		(11.1)
Derivative instruments, gain (loss) recognized in other comprehensive income (loss), Effective portion		(6.1)		(8.6)
Foreign exchange contracts \| Cash flow hedges \| Designated as hedge
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	533.4		533.4		497.7
Interest rate swap contracts \| Fair value hedges \| Designated as hedge
Derivatives, Notional Amount [Line Items]
Notional amount of derivatives	300.0		300.0		$ 0.0
Cost of revenues and operating expenses \| Foreign exchange contracts
Derivatives, Notional Amount [Line Items]
Gain (loss) reclassified	$ (0.8)		$ (1.5)
Cost of revenues and operating expenses \| Foreign exchange contracts \| Cash flow hedges
Derivatives, Notional Amount [Line Items]
Gain (loss) reclassified		$ (3.1)		$ 5.8