v3.4.0.3
Stock incentive plans (Details 3) - Stock options
3 Months Ended
Mar. 31, 2016
Stock incentive plans  
Vesting period 4 years
Vesting percentage when the individual completes 12 months of continuous service 25.00%
Continuous service period of individual 12 months
Vesting percentage on a monthly basis 75.00%