Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3044-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6812-107765

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586

Name:	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Commitments and Contingencies - Additional Information (Detail) ft² in Thousands, $ in Thousands, ¥ in Millions							12 Months Ended
	Feb. 27, 2012 USD ($)	Feb. 27, 2012 CNY (¥)	Oct. 08, 2011 USD ($)	Oct. 08, 2011 CNY (¥)	Sep. 13, 2011 USD ($)	Sep. 13, 2011 CNY (¥)	Mar. 31, 2011 USD ($)	Mar. 31, 2011 CNY (¥)	Mar. 31, 2018 USD ($) ft²	Mar. 31, 2017 USD ($)
Loss Contingencies [Line Items]
Total space leased, square feet \| ft²									187
Restricted cash included in long-term assets \| $									$ 165	$ 165
Sinovel Wind Group Co. Ltd.
Loss Contingencies [Line Items]
Sought compensation amount	$ 17,000	¥ 105	$ 191,000	¥ 1,200
Sinovel Wind Group Co. Ltd.
Loss Contingencies [Line Items]
Sought compensation amount					$ 77,000	¥ 485
Value of the undelivered components							$ 732,000	¥ 4,600