Defined Benefit Plans - Narrative (Details) NAƒ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2019 ANG (NAƒ)
Defined Benefit Plan Disclosure [Line Items]
Restructuring charges	$ 40.2	$ 34.4	$ 41.0
Asset allocation	$ 2,263.4	2,068.1	2,118.7
Defined benefit plan, pension plan with projected benefit obligation, percent	75.00%
U.K. and Plans in Jamaica and Barbados
Defined Benefit Plan Disclosure [Line Items]
Expected future employer contributions in 2018	$ 8.0
Level 1
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	837.4	746.8
Reported Value Measurement | Level 1
Defined Benefit Plan Disclosure [Line Items]
Investments measured at fair value	37.0	35.0
Other assets, net
Defined Benefit Plan Disclosure [Line Items]
Asset allocation	155.0	132.0
Employee severance and termination
Defined Benefit Plan Disclosure [Line Items]
Restructuring charges	$ 30.9	25.6	$ 34.7
C&W | Employee severance and termination
Defined Benefit Plan Disclosure [Line Items]
Restructuring charges		$ 9.0
UTS
Defined Benefit Plan Disclosure [Line Items]
Estimated retirement benefits covered by insurance				$ 36.0	NAƒ 64