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Related Party Transactions - (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Related Party Transaction
Asset impairments		$ 87.0	$ 95.0	$ 87.0	$ 95.0
Dividends paid				$ 441.0	316.0
Disposed of by Sale, Not Discontinued Operations \| Brazilian Venture
Related Party Transaction
Asset impairments	$ 95.0		95.0
Cardinal Holdings
Related Party Transaction
Ownership percentage		38.00%		38.00%		38.00%
Equity method investment		$ 130.0		$ 130.0		$ 151.0
Banco Bradesco \| Corporate joint venture
Related Party Transaction
Ownership percentage						51.00%
Banco Bradesco \| Corporate joint venture
Related Party Transaction
Processing and services revenue			77.0		$ 244.0
Dividends paid			$ 23.0