Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Article 12
-Section 12
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Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current.

+ References

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(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Topic 944
-SubTopic 210
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(6))
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Short Term Investments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	May 23, 2018	Apr. 26, 2018	Mar. 31, 2017
Investment [Line Items]
Short term investments in certificates of deposit	$ 16,000			$ 25,078
Cash Equivalents
Investment [Line Items]
Certificates of deposit	$ 5,000			$ 3,000
Certificates of deposit maturity date	Apr. 26, 2018
Remaining certificates of deposit maturity date	May 23, 2018
Cash Equivalents \| Subsequent Event [Member]
Investment [Line Items]
Certificates of deposit		$ 3,000	$ 2,000