Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Allowance for Doubtful Accounts Receivable
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance, Beginning of Year	$ 16		$ 52
Additions	54	16
Write-offs	(16)		(52)
Balance, End of Year	54	16
Deferred Tax Asset Valuation Allowance
Valuation And Qualifying Accounts Disclosure [Line Items]
Balance, Beginning of Year	282,824	261,961	252,302
Additions	15,189	26,649	21,333
Write-offs	(3,153)	(5,786)	(11,674)
Balance, End of Year	$ 294,860	$ 282,824	$ 261,961

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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Total increases or decreases in allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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