7. Commitments and contingencies (Details) - USD ($)	3 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Mar. 31, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Litigation Settlement, Amount		$ 3,600,000
Loss Contingency, Settlement Agreement, Terms		$25,000
Estimated Litigation Liability, Current		$ 3,625,000	$ 1,635,000	$ 2,838,000
Loss Contingency Accrual, Provision	$ 25,000