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Customers with 10% (or greater) of Net Revenues - Additional Information (Detail) - Entities Owned by One Global Company [Member] - Revenue [Member]	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Customer One [Member]
Concentration Risk [Line Items]
Percentage of concentration	0.057%	10.00%
Customer Two [Member]
Concentration Risk [Line Items]
Percentage of concentration	19.30%
Customer Two [Member] | Maximum [Member]
Concentration Risk [Line Items]
Percentage of concentration	1.00%
Customer Three [Member]
Concentration Risk [Line Items]
Percentage of concentration	13.90%
Customer Three [Member] | Maximum [Member]
Concentration Risk [Line Items]
Percentage of concentration	1.00%
Customer Four [Member]
Concentration Risk [Line Items]
Percentage of concentration	12.60%
Customer Four [Member] | Maximum [Member]
Concentration Risk [Line Items]
Percentage of concentration	1.00%
Customer Five [Member]
Concentration Risk [Line Items]
Percentage of concentration	12.00%
Customer Five [Member] | Maximum [Member]
Concentration Risk [Line Items]
Percentage of concentration	1.00%

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- Definition

Line items represent financial 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.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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