Segment information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014 item	Dec. 31, 2013	Dec. 31, 2012
Segment information
Number of reportable segments	2
Cost of sales included in processing and services costs	$ 13,483,282	$ 13,048,294	$ 11,010,778
Long-lived assets	9,100,000	10,300,000
Number of geographical regions in which the entity conducts its business	3
Net Revenue:
Net revenue	47,368,739	46,566,065	43,578,016
Gross Profit:
Total gross profit	34,919,585	33,650,276	32,634,726
Multi-currency processing services
Segment information
Cost of sales included in processing and services costs	2,000,000	1,700,000
Net Revenue:
Net revenue	30,954,085	29,813,449	28,807,090
Gross Profit:
Total gross profit	28,908,610	28,133,922	28,807,090
Payment processing services
Net Revenue:
Net revenue	16,414,654	16,752,616	14,770,926
Number of individual merchants with revenue greater than 10% of segment revenue	0
Gross Profit:
Total gross profit	6,010,975	5,516,354	3,827,636
APAC | Multi-currency processing services
Net Revenue:
Net revenue	16,621,147	15,666,192	16,248,880
Gross Profit:
Total gross profit	16,513,492	15,572,813	16,248,880
Americas | Multi-currency processing services
Net Revenue:
Net revenue	6,893,337	6,165,431	5,000,064
Gross Profit:
Total gross profit	6,733,037	6,045,441	5,000,064
CEMEA | Multi-currency processing services
Net Revenue:
Net revenue	7,439,601	7,981,826	7,558,146
Gross Profit:
Total gross profit	$ 5,662,081	$ 6,515,668	$ 7,558,146