Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Mar. 31, 2014
Segment Reporting Information [Line Items]
Accounts receivable are due, minimum period (days)		30 days
Accounts receivable are due, maximum period (days)		60 days
Long-term receivables from OTA contracts present value of the future cash flows discounted rate, minimum		8.80%
Long-term receivables from OTA contracts present value of the future cash flows discounted rate, maximum		11.00%
Lease receivable provision write-off	$ 177,000	$ 177,000	$ 0
Inventory obsolescence reserve	1,900,000	1,900,000	1,600,000
Deferred contract costs	46,000	46,000	90,000
Unbilled revenue	55,000	55,000	1,700,000
Deferred financing costs	120,000	$ 120,000	202,000
Deferred financing costs amortized over useful life of debt issue minimum (years)		1 year
Deferred financing costs amortized over useful life of debt issue maximum (years)		3 years
Accrued project costs	200,000	$ 200,000	1,300,000
Product warranty accrual	938,000	$ 938,000	$ 1,015,000	$ 1,043,000	$ 1,116,000	$ 466,000	$ 263,000
Solar power systems completion period minimum (months)		3 months
Solar power systems completion period maximum (months)		15 months
Power purchase agreement product revenue is recognized term (years)		10 years
Deferred tax assets valuation allowance		$ 23,200,000
Orion Engineered Systems
Segment Reporting Information [Line Items]
Product warranty accrual	$ 300,000	$ 300,000
High Intensity Fluorescent Lighting Products
Segment Reporting Information [Line Items]
Limited warranty term (years)		1 year
Minimum
Segment Reporting Information [Line Items]
Length of time of inventory usage considered for inventory reserve (months)		9 months
Minimum | LED Lighting Products
Segment Reporting Information [Line Items]
Limited warranty term (years)		1 year
Maximum
Segment Reporting Information [Line Items]
Length of time of inventory usage considered for inventory reserve (months)		24 months
Maximum | LED Lighting Products
Segment Reporting Information [Line Items]
Limited warranty term (years)		10 years