Revenue - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Disaggregation of revenue
Revenue	$ 1,007,580	$ 1,994,750
U.S. dollar
Disaggregation of revenue
Revenue	916,278	1,805,755
British Pound Sterling
Disaggregation of revenue
Revenue	59,098	122,219
Euro
Disaggregation of revenue
Revenue	25,419	52,016
Other
Disaggregation of revenue
Revenue	6,785	14,760
Volume-based revenues
Disaggregation of revenue
Revenue	752,462	1,480,402
Non-volume related revenues
Disaggregation of revenue
Revenue	255,118	514,348
Issuer Solutions
Disaggregation of revenue
Revenue	458,601	915,960
Issuer Solutions | U.S. dollar
Disaggregation of revenue
Revenue	367,489	727,359
Issuer Solutions | British Pound Sterling
Disaggregation of revenue
Revenue	59,098	122,219
Issuer Solutions | Euro
Disaggregation of revenue
Revenue	25,419	52,016
Issuer Solutions | Other
Disaggregation of revenue
Revenue	6,595	14,366
Issuer Solutions | Volume-based revenues
Disaggregation of revenue
Revenue	223,677	442,949
Issuer Solutions | Non-volume related revenues
Disaggregation of revenue
Revenue	234,924	473,011
Merchant Solutions
Disaggregation of revenue
Revenue	348,714	668,137
Merchant Solutions | U.S. dollar
Disaggregation of revenue
Revenue	348,524	667,743
Merchant Solutions | Other
Disaggregation of revenue
Revenue	190	394
Merchant Solutions | Volume-based revenues
Disaggregation of revenue
Revenue	329,295	628,242
Merchant Solutions | Non-volume related revenues
Disaggregation of revenue
Revenue	19,419	39,895
Consumer Solutions
Disaggregation of revenue
Revenue	200,265	410,653
Consumer Solutions | U.S. dollar
Disaggregation of revenue
Revenue	200,265	410,653
Consumer Solutions | Volume-based revenues
Disaggregation of revenue
Revenue	199,490	409,211
Consumer Solutions | Non-volume related revenues
Disaggregation of revenue
Revenue	$ 775	$ 1,442