Participation and Contributions to Multi Employer Pension Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Multiemployer Plans [Line Items]
Partnership Contributions	$ 9,141	$ 8,940	$ 8,383
New England Teamsters & Trucking Industry Pension Fund
Multiemployer Plans [Line Items]
EIN	046372430
Pension Plan Number	001
Pension Protection Act Zone Status	Red	Red
FIP / RP Status Pending / Implemented	Implemented
Partnership Contributions	$ 2,455	$ 2,621	2,507
Surcharge Imposed	No
Expiration Date of Collective-Bargaining Agreements, Start Date	Sep. 30, 2018
Expiration Date of Collective-Bargaining Agreements, End Date	Apr. 30, 2021
Westchester Teamsters Pension Fund
Multiemployer Plans [Line Items]
EIN	136123973
Pension Plan Number	001
Pension Protection Act Zone Status	Green	Green
FIP / RP Status Pending / Implemented	NA
Partnership Contributions	$ 846	$ 924	865
Surcharge Imposed	No
Expiration Date of Collective-Bargaining Agreements, Start Date	Jan. 31, 2019
Expiration Date of Collective-Bargaining Agreements, End Date	Dec. 31, 2019
Local 553 Pension Fund
Multiemployer Plans [Line Items]
EIN	136637826
Pension Plan Number	001
Pension Protection Act Zone Status	Green	Green
FIP / RP Status Pending / Implemented	NA
Partnership Contributions	$ 2,888	$ 2,780	2,645
Surcharge Imposed	No
Expiration Date of Collective-Bargaining Agreements, Start Date	Dec. 15, 2019
Expiration Date of Collective-Bargaining Agreements, End Date	Jan. 15, 2020
Local 463 Pension Fund
Multiemployer Plans [Line Items]
EIN	111800729
Pension Plan Number	001
Pension Protection Act Zone Status	Green	Green
FIP / RP Status Pending / Implemented	NA
Partnership Contributions	$ 145	$ 150	148
Surcharge Imposed	No
Expiration Date of Collective-Bargaining Agreements, End Date	Feb. 28, 2020
All Other Multiemployer Pension Plans
Multiemployer Plans [Line Items]
Partnership Contributions	$ 2,807	$ 2,465	$ 2,218

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Amount of contributions made to multiemployer plan by employer.

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-Topic 715
-SubTopic 80
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Three digit plan number for a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Indicate the multiemployer plan's certified zone status as currently required by the Pension Protection Act of 2006 or a subsequent amendment thereof. The zone status categories are red (critical status), orange (seriously endangered), yellow (endangered), and green (none of the above). The acceptable values are "red", "orange", "yellow", "green", "other", and "NA". A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Expiration date of the collective bargaining arrangement requiring contributions to the multiemployer plan that will expire first in a group of associated collective bargaining arrangements, in CCYY-MM-DD format. A multiemployer plan is a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

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Indicate whether the employer paid a surcharge to the pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers. The acceptable values are "no", "yes", and "NA".

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