Commitments and contingencies (Details) - Jun. 30, 2015	USD ($) Executive Customer State
Viatek Consumer Product Group, Inc. [Member]
Loss Contingencies [Line Items]
Litigation settlement amount received	$ 82,510.24
Eastern District of Pennsylvania [Member]
Loss Contingencies [Line Items]
Number of executives | Executive	2
Court awarded settlement amount	$ 1,500,000
LCA Vision Inc [Member]
Loss Contingencies [Line Items]
Maximum possible contribution to settlement	$ 100,000
Radiancy, Inc. [Member]
Loss Contingencies [Line Items]
Number of customers | Customer	12
Number of states | State	10