Commitments and Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($)
Long-term Purchase Commitment [Line Items]
Aggregate residual value at lease expiration for vehicle leases	$ 11,986
Guaranteed aggregate residual value at lease expiration for vehicle leases	9,681
Liability for the estimated end of term loss related to residual value guarantee	404
Green Machine supply commitment
Long-term Purchase Commitment [Line Items]
Purchase obligation, due in next twelve months	12,000
Long-term purchase commitment, amount	$ 24,000
Long-term purchase commitment, period	2 years
Software development arrangement
Long-term Purchase Commitment [Line Items]
Purchase obligation, due in next twelve months	$ 3,000
Long-term purchase commitment, amount	$ 8,000
Long-term purchase commitment, period	4 years