Restructuring - Restructuring Charges By Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 65.0	$ 49.4	$ 59.4
Severance | Eurasia Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	37.1	24.6	33.2
Severance | Americas Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	8.9	4.2	13.8
Severance | Retail Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	13.3	14.8	0.7
Severance | Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 5.7	$ 5.8	$ 11.7