Segment Reporting and Major Customers - Geographic Revenues to External Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Geographic revenues to external revenues by operating segment
Total revenues	$ 1,035,485	$ 1,007,580	$ 2,070,016	$ 1,994,750
United States
Geographic revenues to external revenues by operating segment
Total revenues	804,846	814,551	1,639,465	1,607,721
Europe
Geographic revenues to external revenues by operating segment
Total revenues	99,166	89,466	193,713	184,735
Canada
Geographic revenues to external revenues by operating segment
Total revenues	107,790	81,355	187,811	159,215
Other
Geographic revenues to external revenues by operating segment
Total revenues	23,683	22,208	49,027	43,079
Issuer Solutions
Geographic revenues to external revenues by operating segment
Total revenues	472,706	458,601	942,865	915,960
Issuer Solutions | United States
Geographic revenues to external revenues by operating segment
Total revenues	243,000	266,274	514,130	530,306
Issuer Solutions | Europe
Geographic revenues to external revenues by operating segment
Total revenues	99,038	89,339	193,425	184,483
Issuer Solutions | Canada
Geographic revenues to external revenues by operating segment
Total revenues	107,368	81,076	187,001	158,657
Issuer Solutions | Other
Geographic revenues to external revenues by operating segment
Total revenues	23,300	21,912	48,309	42,514
Merchant Solutions
Geographic revenues to external revenues by operating segment
Total revenues	366,636	348,714	711,817	668,137
Merchant Solutions | United States
Geographic revenues to external revenues by operating segment
Total revenues	365,703	348,012	710,001	666,762
Merchant Solutions | Europe
Geographic revenues to external revenues by operating segment
Total revenues	128	127	288	252
Merchant Solutions | Canada
Geographic revenues to external revenues by operating segment
Total revenues	422	279	810	558
Merchant Solutions | Other
Geographic revenues to external revenues by operating segment
Total revenues	383	296	718	565
Consumer Solutions
Geographic revenues to external revenues by operating segment
Total revenues	196,143	200,265	415,334	410,653
Consumer Solutions | United States
Geographic revenues to external revenues by operating segment
Total revenues	$ 196,143	$ 200,265	$ 415,334	$ 410,653