Expiration Years of Minimum Alternate Tax Credit (Detail) - Minimum Alternate Tax (MAT) $ in Thousands	Sep. 30, 2017 USD ($)
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	$ 42,390
Less: valuation allowance	(2,450)
Total (net of valuation allowance)	39,940
2022-2023
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	180
2023-2024
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	270
2024-2025
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	990
2025-2026
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	1,830
2026-2027
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	740
2027-2028
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	6,090
2028-2029
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	7,220
2029-2030
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	7,920
2030-2031
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	10,190
2031-2032
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	5,470
2032-2033
Tax Credit Carryforward [Line Items]
Minimum Alternate Tax Credit	$ 1,490

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b),(c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
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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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