Commitments and Contingencies - Summary of Accrued Warranty Activity (Details) - Solar Energy System Performance Warranty - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2016	Jun. 28, 2015	May 31, 2016	Jun. 28, 2015
Product Warranty Liability [Line Items]
Balance at the beginning of the period	$ 226	$ 487	$ 237	$ 525
Settlements during the period	(80)	(58)	(156)	(120)
Adjustments during the period	(6)	(9)	59	15
Balance at the end of the period	$ 140	$ 420	$ 140	$ 420