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Nature of the Business and Operations and Liquidity - Additional Information (Detail) $ in Thousands					1 Months Ended	3 Months Ended	12 Months Ended			72 Months Ended
	Mar. 28, 2018 USD ($)	Feb. 01, 2018 USD ($)	May 10, 2017 USD ($)	Apr. 04, 2017	Dec. 31, 2015 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($) employee	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2018 USD ($) employee	Mar. 31, 2015 USD ($)
Description Of Business [Line Items]
Accumulated deficit						$ (955,557)	$ (988,333)	$ (955,557)		$ (988,333)
Cash and cash equivalents						26,784	34,084	26,784	$ 39,330	$ 34,084	$ 20,490
Net Cash Provided by (Used in) Operating Activities							(24,827)	(11,215)	(4,559)
Number of positions eliminated, period percent				8.00%
Restructuring and impairment							$ 1,527
Number of workforce persons | employee							247			247
Cash flows from financing activities										$ 85,200
Proceeds from ATM sales, net						2,500	$ 0	2,527	$ 0
Purchase and sale agreement, total consideration	$ 23,000
Note receivable						$ 0	$ 2,559	$ 0		$ 2,559
64 Jackson LLC
Description Of Business [Line Items]
Purchase and sale agreement, total consideration	23,000	$ 23,000
Purchase and sale agreement, sale of property	17,000
Note receivable	6,000	$ 6,000
Purchase and sale agreement, proceeds from sale of property, plant and equipment, net	$ 16,900
Interest rate	1.96%						1.96%			1.96%
Inox Wind Limited
Description Of Business [Line Items]
Strategic agreements value					$ 210,000
Supply commitment, extension period					3 years
Common Stock
Description Of Business [Line Items]
Proceeds from additional equity offering			$ 17,000

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