Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill	$ 1,234.9	$ 1,234.9	$ 1,269.1	$ 1,336.4
Accumulated impairment losses	(470.9)	(470.9)	(470.9)	(290.7)
Beginning balance		798.2	1,045.7
Transferred to assets held for sale		(11.7)	(44.5)
Currency translation adjustment		(18.2)	(22.8)
Impairment	0.0		(180.2)
Divestitures		(4.3)
Ending balance	764.0	764.0	798.2
Eurasia Banking Segment [Member]
Goodwill [Line Items]
Goodwill	579.2	579.2	598.6	608.3
Accumulated impairment losses	(291.7)	(291.7)	(291.7)	(168.7)
Beginning balance		306.9	439.6
Transferred to assets held for sale		(11.7)	(0.8)
Currency translation adjustment		(7.3)	(8.9)
Impairment			(123.0)
Divestitures		(0.4)
Ending balance	287.5	287.5	306.9
Americas Banking Segment [Member]
Goodwill [Line Items]
Goodwill	431.3	431.3	437.3	445.0
Accumulated impairment losses	(122.0)	(122.0)	(122.0)	(122.0)
Beginning balance		315.3	323.0
Transferred to assets held for sale		0.0	(0.3)
Currency translation adjustment		(6.0)	(7.4)
Impairment			0.0
Divestitures		0.0
Ending balance	309.3	309.3	315.3
Retail Segment [Member]
Goodwill [Line Items]
Goodwill	224.4	224.4	233.2	283.1
Accumulated impairment losses	(57.2)	(57.2)	(57.2)	$ 0.0
Beginning balance		176.0	283.1
Transferred to assets held for sale		0.0	(43.4)
Currency translation adjustment		(4.9)	(6.5)
Impairment			(57.2)
Divestitures		(3.9)
Ending balance	$ 167.2	$ 167.2	$ 176.0