Goodwill and intangible assets (Tables)

12 Months Ended

Dec. 31, 2013

Goodwill and intangible assets

Schedule of changes in carrying amount of goodwill

Goodwill, gross, as of December 31, 2011	$	—
Acquisition of BPS		335,791
Impact of change in Euro exchange rate		11,808
Accumulated impairment losses as of December 31, 2012		—
Goodwill, gross, as of December 31, 2012		347,599
Impact of change in Euro exchange rate		14,464
Accumulated impairment losses as of December 31, 2013		—
Goodwill, net, as of December 31, 2013	$	362,063

Schedule of the gross book value, accumulated amortization and amortization periods of intangible assets

	As of December 31, 2013							As of December 31, 2012
	Gross book value		Accumulated amortization			Net book value		Gross book value		Accumulated amortization			Net book value		Amortization period (in years)
Trademarks and patents	$	1,100,696	$	(327,200	)	$	773,496	$	917,456	$	(258,325	)	$	659,131		15
Technology		3,015,192		(967,779	)		2,047,413		2,894,742		(351,018	)		2,543,724		5
Customer contracts		867,354		(867,354	)		—		867,354		(780,619	)		86,735		5
Intangible assets, net	$	4,983,242	$	(2,162,333	)	$	2,820,909	$	4,679,552	$	(1,389,962	)	$	3,289,590

Schedule of amortization expense related to intangible assets

	Year ended December 31,
	2013		2012		2011
Amortization expense	$	735,265	$	569,721	$	224,486

Schedule of intangible amortization expense that will be charged to income and is estimated on the basis of book value

2014	$	677,007
2015		675,774
2016		675,378
2017		309,773
2018		70,912
Thereafter		412,065
Total	$	2,820,909