Derivative Financial Instruments - Narrative (Details) - Designated as Hedging Instrument - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Foreign Currency Hedges
Derivative [Line Items]
Gains reported in accumulated other comprehensive income			$ 0.4
Gain to be reclassified within next 12 months			0.4
Derivatives, net gain (loss) reclassified into cost of services	$ 0.4	$ (0.6)	0.9	$ (1.0)
Notional amount	29.5		29.5		$ 52.0
Interest Rate Swap
Derivative [Line Items]
Gains reported in accumulated other comprehensive income			0.0
Gain to be reclassified within next 12 months			0.0
Derivatives, net gain (loss) reclassified into cost of services	0.0	$ 0.0	0.0	$ 0.0
Notional amount	$ 100.0		$ 100.0		$ 0.0