Commitment and Contingencies (Details 2) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Soroof Trading Company Ltd.
Commitments and Contingencies
Liability related to litigation	$ 2.4
GenDrive contracts
Commitments and Contingencies
Product warranty period, Minimum	1 year
Product warranty period, Maximum	2 years
ReliOn contracts
Commitments and Contingencies
Product warranty period, Minimum	2 years
Product warranty period, Maximum	5 years