Revenue Recognition - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 306,602	$ 318,270	$ 1,349,405
Service
Disaggregation of Revenue [Line Items]
Revenues	291,854	302,602
Surcharge revenues
Disaggregation of Revenue [Line Items]
Revenues	128,776	136,823
Interchange revenues
Disaggregation of Revenue [Line Items]
Revenues	77,480	90,990
Bank-branding and surcharge-free network revenues
Disaggregation of Revenue [Line Items]
Revenues	54,115	45,873
Managed services and processing revenues
Disaggregation of Revenue [Line Items]
Revenues	31,483	28,916
Product and Service, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	14,748	15,668
North America
Disaggregation of Revenue [Line Items]
Revenues	204,382	201,664
Europe & Africa
Disaggregation of Revenue [Line Items]
Revenues	81,863	90,596
Australia & New Zealand
Disaggregation of Revenue [Line Items]
Revenues	20,357	26,010
Operating Segments | North America
Disaggregation of Revenue [Line Items]
Revenues	205,997	204,248
Operating Segments | North America | Service
Disaggregation of Revenue [Line Items]
Revenues	193,241	191,046
Operating Segments | North America | Surcharge revenues
Disaggregation of Revenue [Line Items]
Revenues	80,235	85,110
Operating Segments | North America | Interchange revenues
Disaggregation of Revenue [Line Items]
Revenues	31,610	34,379
Operating Segments | North America | Bank-branding and surcharge-free network revenues
Disaggregation of Revenue [Line Items]
Revenues	53,768	45,873
Operating Segments | North America | Managed services and processing revenues
Disaggregation of Revenue [Line Items]
Revenues	27,628	25,684
Operating Segments | North America | Product and Service, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	12,756	13,202
Operating Segments | Europe & Africa
Disaggregation of Revenue [Line Items]
Revenues	81,900	90,925
Operating Segments | Europe & Africa | Service
Disaggregation of Revenue [Line Items]
Revenues	79,958	88,678
Operating Segments | Europe & Africa | Surcharge revenues
Disaggregation of Revenue [Line Items]
Revenues	32,596	31,045
Operating Segments | Europe & Africa | Interchange revenues
Disaggregation of Revenue [Line Items]
Revenues	44,997	55,308
Operating Segments | Europe & Africa | Bank-branding and surcharge-free network revenues
Disaggregation of Revenue [Line Items]
Revenues	347	0
Operating Segments | Europe & Africa | Managed services and processing revenues
Disaggregation of Revenue [Line Items]
Revenues	2,018	2,325
Operating Segments | Europe & Africa | Product and Service, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,942	2,247
Operating Segments | Australia & New Zealand
Disaggregation of Revenue [Line Items]
Revenues	20,357	26,010
Operating Segments | Australia & New Zealand | Service
Disaggregation of Revenue [Line Items]
Revenues	20,307	25,791
Operating Segments | Australia & New Zealand | Surcharge revenues
Disaggregation of Revenue [Line Items]
Revenues	15,945	20,668
Operating Segments | Australia & New Zealand | Interchange revenues
Disaggregation of Revenue [Line Items]
Revenues	873	1,303
Operating Segments | Australia & New Zealand | Bank-branding and surcharge-free network revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Operating Segments | Australia & New Zealand | Managed services and processing revenues
Disaggregation of Revenue [Line Items]
Revenues	3,489	3,820
Operating Segments | Australia & New Zealand | Product and Service, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	50	219
Eliminations
Disaggregation of Revenue [Line Items]
Revenues	1,652	2,913
Eliminations | Service
Disaggregation of Revenue [Line Items]
Revenues	1,652	2,913
Eliminations | Surcharge revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Eliminations | Interchange revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Eliminations | Bank-branding and surcharge-free network revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Eliminations | Managed services and processing revenues
Disaggregation of Revenue [Line Items]
Revenues	1,652	2,913
Eliminations | Product and Service, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	0	0
Eliminations | North America
Disaggregation of Revenue [Line Items]
Revenues	(1,615)	(2,584)
Eliminations | Europe & Africa
Disaggregation of Revenue [Line Items]
Revenues	(37)	(329)
Eliminations | Australia & New Zealand
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0