Segment information (Details 2) (Revenue, Geographical concentration risk, Multi-currency processing services)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
APAC | Customer A
Revenue concentration
Concentration risk (as a percent)	63.00%	61.00%	64.00%	62.00%
APAC | Customer E
Revenue concentration
Concentration risk (as a percent)		13.00%		13.00%
North America | Customer F
Revenue concentration
Concentration risk (as a percent)	29.00%	16.00%	29.00%	16.00%
North America | Customer G
Revenue concentration
Concentration risk (as a percent)	27.00%	43.00%	31.00%	47.00%
North America | Customer H
Revenue concentration
Concentration risk (as a percent)	11.00%	11.00%	10.00%	12.00%
CEMEA | Customer C
Revenue concentration
Concentration risk (as a percent)	74.00%	100.00%	77.00%	100.00%
CEMEA | Customer I
Revenue concentration
Concentration risk (as a percent)	26.00%		23.00%