Identifiable intangible assets (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Software costs capitalized	$ 994,000	$ 661,000
Amortization of capitalized software costs	464,000	92,000
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	19,434,000		18,440,000
Less accumulated amortization	(3,833,000)		(3,369,000)
Intangible assets - net	15,601,000		15,071,000
Future amortization of intangible assets assuming straight-line amortization of capitalized software costs [Abstract]
2014	1,767,000
2015	2,256,000
2016	2,225,000
2017	2,125,000
2018	2,023,000
Thereafter	3,405,000
Total	13,801,000
Acquired and internally developed software costs [Member]
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	17,634,000		16,640,000
Trademarks (non-amortizable) [Member]
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	$ 1,800,000		$ 1,800,000
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining estimated economic life of the product	3 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Remaining estimated economic life of the product	7 years