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Basis of Presentation and Revenue Recognition (Details) - Segment
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Basis of Presentation and Revenue Recognition [Abstract]        
Number of reportable segment     2  
Term of warranty (in years)     1 year  
Period of post customer support service (PCS) (in years)     1 year  
Revenue [Member]        
Revenue by major customers [Abstract]        
Concentration Risk, Benchmark Description     the following customers provided more than 10% of the Company’s consolidated revenue  
Revenue [Member] | Tennessee Valley Authority [Member]        
Revenue by major customers [Abstract]        
Percentage of revenue contributed by major customers (in hundredths) 14.30% 0.00% 17.90% 0.00%
Revenue [Member] | Public Service Enterprise Group Inc. [Member]        
Revenue by major customers [Abstract]        
Percentage of revenue contributed by major customers (in hundredths) 11.30% 0.60% 10.60% 0.60%