Goodwill and Intangible Assets - Intangible assets, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Intangible assets with finite lives:
Net	$ 291,766		$ 291,766		$ 294,997
Total intangible assets, net	310,265		310,265		313,483
Amortization expense related to intangible assets	11,500	$ 11,400	22,200	$ 21,300
Trademarks
Intangible assets with finite lives:
Gross carrying value	18,499		18,499		18,486
Merchant contract portfolios
Intangible assets with finite lives:
Gross carrying value	282,614		282,614		274,780
Accumulated amortization	(125,515)		(125,515)		(113,747)
Accumulated impairment losses	(5,658)		(5,658)		(5,658)
Foreign currency translation adjustment	(28,443)		(28,443)		(26,057)
Net	122,998		122,998		129,318
Marketing alliance agreements
Intangible assets with finite lives:
Gross carrying value	191,954		191,954		187,758
Accumulated amortization	(41,694)		(41,694)		(35,509)
Accumulated impairment losses	(7,585)		(7,585)		(7,585)
Foreign currency translation adjustment	(17,671)		(17,671)		(15,561)
Net	125,004		125,004		129,103
Trademarks
Intangible assets with finite lives:
Gross carrying value	27,283		27,283		25,084
Accumulated amortization	(9,596)		(9,596)		(8,485)
Foreign currency translation adjustment	(4,355)		(4,355)		(3,701)
Net	13,332		13,332		12,898
Internally developed software
Intangible assets with finite lives:
Gross carrying value	52,620		52,620		42,442
Accumulated amortization	(11,696)		(11,696)		(9,760)
Accumulated impairment losses	(9,324)		(9,324)		(9,324)
Foreign currency translation adjustment	(3,607)		(3,607)		(3,247)
Net	27,993		27,993		20,111
Non-competition agreements
Intangible assets with finite lives:
Gross carrying value	6,400		6,400		6,200
Accumulated amortization	(3,961)		(3,961)		(2,633)
Net	$ 2,439		$ 2,439		$ 3,567