Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Other Commitments (Details)

v3.7.0.1
Commitments and Contingencies - Other Commitments (Details)
$ in Millions
1 Months Ended
Jul. 18, 2016
action
Sep. 30, 2010
USD ($)
kW
Dec. 18, 2015
complaint
Sep. 30, 2015
USD ($)
Legal matters        
Number of putative securities class action complaints filed against the Company | complaint     2  
Number of additional purported shareholder derivative actions filed | action 2      
Research, development and testing of a more efficient microturbine Combined Heat and Power (CHP) system        
Commitments and Contingencies        
Projected electrical efficiency of microturbine (as a percent)   42.00%    
Power output of microturbine (in kW) | kW   370    
Term of contract   5 years    
Projected cost of research, development and testing project   $ 11.7    
Contribution by DOE   4.2    
Expense to be incurred by the company in research and development   6.7    
Cumulative amount of bill under contract       $ 4.2
Research, development and testing of a more efficient microturbine Combined Heat and Power (CHP) system | DOE        
Commitments and Contingencies        
Contribution by DOE   $ 5.0