Identifiable intangible assets (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Software costs capitalized	$ 732,000	$ 1,590,000	$ 2,257,000	$ 3,216,000
Amortization of capitalized software costs	477,000	402,000	1,411,000	894,000
Amortization of identifiable intangible assets	31,000	0	31,000	0
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	27,894,000		27,894,000		18,440,000
Less accumulated amortization	(4,810,000)		(4,810,000)		(3,369,000)
Intangible assets - net	23,084,000		23,084,000		15,071,000
Future amortization of intangible assets assuming straight-line amortization of capitalized software costs [Abstract]
2014	782,000		782,000
2015	3,445,000		3,445,000
2016	3,414,000		3,414,000
2017	3,313,000		3,313,000
2018	3,211,000		3,211,000
Thereafter	7,119,000		7,119,000
Total	21,284,000		21,284,000
Acquired and internally developed software costs [Member]
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	26,094,000		26,094,000		16,640,000
Trademarks (non-amortizable) [Member]
Components of identifiable intangible assets [Abstract]
Intangible assets - gross	$ 1,800,000		$ 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