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Restructuring - Additional Information (Detail) |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 78 Months Ended |  |
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Nov. 11, 2015 Employees | Oct. 20, 2015 Position | Apr. 26, 2013 Employees | Jan. 31, 2014 USD ($) | Mar. 31, 2016 USD ($) | Mar. 31, 2015 USD ($) | Mar. 31, 2016 USD ($) | Mar. 31, 2015 USD ($) | Mar. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Sep. 30, 2015 USD ($)
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Other charges |  |  |  |  |  | $ 3,000,000 |  |  |  |  |
Restructuring costs in accrued expenses |  |  |  |  | $ 13,000,000 |  | $ 13,000,000 |  | $ 13,000,000 | $ 22,000,000 | $ 9,000,000
Restructuring Activities Other [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  |  | 1,000,000 | $ 4,000,000 |  |  |
Severance and Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Restructuring costs in accrued expenses |  |  |  |  | 11,000,000 |  | 11,000,000 |  | 11,000,000 | 19,000,000 | 5,000,000
Environmental Remediation [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Restructuring costs in accrued expenses |  |  |  |  | 2,000,000 |  | 2,000,000 |  | 2,000,000 | $ 2,000,000 | $ 2,000,000
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Benefit |  |  |  |  | 1,000,000 |  |  |  |  |  |
Maximum [Member] | Restructuring Activities Other [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Additional restructuring charges remainder of fiscal 2016 and thereafter |  |  |  |  |  |  | 1,000,000 |  |  |  |
Maximum [Member] | Severance Costs [Member] | Restructuring Activities Other [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Accrued severance charges |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Operational Restructuring [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of positions eliminated | Position |  | 300 |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  | 2,000,000 |  | 26,000,000 |  |  |  |
Additional restructuring charges through the reminder of fiscal 2016 |  |  |  |  |  |  | 2,000,000 |  |  |  |
Expected cumulative net cash outlays related to plan |  |  |  |  | 29,000,000 |  | 29,000,000 |  | 29,000,000 |  |
Cash payments |  |  |  |  |  |  | 18,000,000 |  |  |  |
Restructuring cash payments through the reminder of fiscal 2016 |  |  |  |  |  |  | 9,000,000 |  |  |  |
Restructuring cash payments, thereafter |  |  |  |  |  |  | 2,000,000 |  |  |  |
Operational Restructuring [Member] | Severance Costs [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Accrued severance charges |  |  |  |  | 8,000,000 |  | 8,000,000 |  | 8,000,000 |  |
Operational Restructuring [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Additional restructuring charges after current fiscal |  |  |  |  |  |  | 1,000,000 |  |  |  |
Closure of Carbon Black Facility [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  |  | 25,000,000 |  |  |  |
Expected cumulative net cash outlays related to plan |  |  |  |  | 8,000,000 |  | 8,000,000 |  | 8,000,000 |  |
Cash payments |  |  |  |  |  |  | 2,000,000 |  |  |  |
Restructuring cash payments through the reminder of fiscal 2016 |  |  |  |  |  |  | 6,000,000 |  |  |  |
Affected employees | Employees | 50 |  |  |  |  |  |  |  |  |  |
Site demolition and other miscellaneous costs through the remainder of fiscal 2016 |  |  |  |  |  |  | 5,000,000 |  |  |  |
Severance charges |  |  |  |  |  |  | 2,000,000 |  |  |  |
Other charges |  |  |  |  |  |  | 1,000,000 |  |  |  |
Severance and other charges |  |  |  |  |  |  | 1,000,000 |  |  |  |
Closure of Carbon Black Facility [Member] | Severance Costs [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Accrued severance charges |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Closure of Carbon Black Facility [Member] | Asset Impairment and Accelerated Depreciation [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  | 1,000,000 |  | 23,000,000 |  |  |  |
Closure of Carbon Black Facility [Member] | Severance and Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  |  | 2,000,000 |  |  |  |
Shared Service Center Transition [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  | $ 24,000,000 |  |  | 0 | 5,000,000 |  |  |
Cash payments |  |  |  |  |  |  | 20,000,000 |  |  |  |
Severance charges |  |  |  | 16,000,000 |  |  | 13,000,000 | 1,000,000 |  |  |
Other charges |  |  |  | $ 8,000,000 |  |  | 7,000,000 | 4,000,000 |  |  |
Expected severance charges |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Restructuring costs in accrued expenses |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Closure of Port Dickson [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  |  | 19,000,000 |  |  |  |
Affected employees | Employees |  |  | 90 |  |  |  |  |  |  |  |
Severance charges |  |  |  |  |  |  | 2,000,000 |  |  |  |
Other charges |  |  |  |  |  |  | 1,000,000 |  |  |  |
Net pre-tax gain |  |  |  |  |  |  | 1,000,000 |  |  |  |
Accelerated depreciation and asset write-offs |  |  |  |  |  |  | 16,000,000 |  |  |  |
Site demolition, clearing and environmental remediation costs |  |  |  |  |  |  | 2,000,000 |  |  |  |
Expected cumulative net cash received to this plan |  |  |  |  | 3,000,000 |  | $ 3,000,000 |  | $ 3,000,000 |  |
Closure of Port Dickson [Member] | Land [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gain on sale of asset |  |  |  |  | $ 2,000,000 |  |  |  |  |  |
Closure of Port Dickson [Member] | Cabot [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Equity share in CMSB |  |  | 50.10% |  |  |  |  |  |  |  |
Closure of Port Dickson [Member] | CMSB [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Portion of the charges that are allocable to the noncontrolling interest |  |  |  |  | 49.90% |  | 49.90% |  | 49.90% |  |
Closure of Port Dickson [Member] | Severance and Employee Benefits [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Expected cumulative net cash received to this plan |  |  |  |  | $ 2,000,000 |  | $ 2,000,000 |  | $ 2,000,000 |  |
Closure of Port Dickson [Member] | Asset Sales [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Expected cumulative net cash received to this plan |  |  |  |  | 7,000,000 |  | 7,000,000 |  | 7,000,000 |  |
Closure of Port Dickson [Member] | Environmental Remediation [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Expected cumulative net cash received to this plan |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Closure of Port Dickson [Member] | Facility Closure Costs [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Expected cumulative net cash received to this plan |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Closure of Port Dickson [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  | 1,000,000 | 1,000,000 | 1,000,000 | 1,000,000 |  |  |
Restructuring cash payments through the reminder of fiscal 2016 |  |  |  |  |  |  | 1,000,000 |  |  |  |
Restructuring costs in accrued expenses |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 1,000,000 |  |
Previous Actions and Sites Pending Sale [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  |  |  | $ 2,000,000 |  |  |
Cash payments |  |  |  |  |  |  |  |  | 78,000,000 |  |
Severance charges |  |  |  |  | 67,000,000 |  |  |  | 63,000,000 |  |
Other charges |  |  |  |  | 23,000,000 |  |  |  | 24,000,000 |  |
Expected severance charges |  |  |  |  | 158,000,000 |  | 158,000,000 |  | 158,000,000 |  |
Net pre-tax gain |  |  |  |  |  |  | 7,000,000 |  |  |  |
Gain on sale of asset |  |  |  |  | 8,000,000 |  |  |  |  |  |
Site demolition, clearing and environmental remediation costs |  |  |  |  | 10,000,000 |  |  |  | 10,000,000 |  |
Restructuring accelerated depreciation and asset impairments |  |  |  |  | 66,000,000 |  |  |  |  |  |
Proceeds from sale of Assets |  |  |  |  |  |  |  |  | 19,000,000 |  |
Previous Actions and Sites Pending Sale [Member] | Land Rights [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Gain on sale of asset |  |  |  |  | 7,000,000 |  |  |  |  |  |
Previous Actions and Sites Pending Sale [Member] | Severance Costs [Member] | Restructuring Activities Other [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Accrued severance charges |  |  |  |  | $ 2,000,000 |  | 2,000,000 |  | $ 2,000,000 |  |
Previous Actions and Sites Pending Sale [Member] | Environmental and Other Closure Related Costs [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Restructuring cash payments through the reminder of fiscal 2016 and thereafter |  |  |  |  |  |  | $ 2,000,000 |  |  |  |
Previous Actions and Sites Pending Sale [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |
Restructuring Cost And Reserve [Line Items] |  |  |  |  |  |  |  |  |  |  |
Pre-tax charge to earnings |  |  |  |  |  | $ 1,000,000 |  |  |  |  |

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