New Accounting Pronouncements (Policies)	6 Months Ended
Mar. 27, 2020
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Use of Estimates and Assumptions	The preparation of financial statements in conformity with U.S. GAAP requires us to employ estimates and make assumptions that affect the reported amounts of certain assets and liabilities, the revenues and expenses reported for the periods covered by the accompanying consolidated financial statements, and certain amounts disclosed in these Notes to the Consolidated Financial Statements. Although such estimates and assumptions are based on management’s most recent assessment of the underlying facts and circumstances utilizing the most current information available and past experience including considerations for potential impacts of the coronavirus (COVID-19) pandemic, actual results could differ significantly from those estimates and assumptions. Our estimates, judgments, and assumptions are evaluated periodically and adjusted accordingly. Please refer to Note 2- Significant Accounting Policies of Notes to Consolidated Financial Statements included in our 2019 Form 10-K for a discussion of other significant estimates and assumptions affecting our consolidated financial statements.
Fair Value and Fair Value Measurements	Certain amounts included in the accompanying consolidated financial statements are presented at “fair value.” Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants as of the date fair value is determined (the “measurement date”). When determining fair value, we consider the principal or most advantageous market in which we would transact, and we consider only those assumptions we believe a typical market participant would consider when pricing an asset or liability. In measuring fair value, we use the following inputs in the order of priority indicated: Level 1 - Quoted prices in active markets for identical assets or liabilities. Level 2 - Observable inputs other than quoted prices in active markets included in Level 1, such as (i) quoted prices for similar assets or liabilities; (ii) quoted prices in markets that have insufficient volume or infrequent transactions (e.g., less active markets); and (iii) model-driven valuations in which all significant inputs are observable or can be derived principally from, or corroborated with, observable market data for substantially the full term of the asset or liability. Level 3 - Unobservable inputs to the valuation methodology that are significant to the fair value measurement. Please refer to Note 2- Significant Accounting Policies of Notes to Consolidated Financial Statements included in our 2019 Form 10-K for a more complete discussion of the various items within the consolidated financial statements measured at fair value and the methods used to determine fair value. Please also refer to Note 7- Sale of Energy, Chemicals and Resources for discussion regarding the Company's investment in Worley ordinary shares. The net carrying amounts of cash and cash equivalents, trade receivables and payables and short-term debt approximate fair value due to the short-term nature of these instruments. See Note 12- Borrowings for a discussion of the fair value of long-term debt.
New Accounting Pronouncements	In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging ("ASC 815"): Targeted Improvements to Accounting for Hedging Activities. ASU 2017-12 provides financial reporting improvements related to hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. Additionally, ASU No. 2017-12 makes certain targeted improvements to simplify the application of the hedge accounting guidance. The revised guidance is effective for fiscal years beginning after December 15, 2018 with early adoption permitted. The updated guidance did not have a significant impact on the Company’s consolidated financial statements. ASU 2017-04, Simplifying the Test for Goodwill Impairment, is effective for fiscal years beginning after December 15, 2019 with early adoption permitted. ASU 2017-04 removes the second step of the goodwill impairment test, which requires a hypothetical purchase price allocation. An entity will now recognize a goodwill impairment charge for the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the amount of goodwill allocated to the reporting unit. Management does not expect the adoption of ASU 2017-04 to have a material impact on the Company's financial position, results of operations or cash flows. ASU No. 2016-13, Financial Instruments - Credit Losses ("ASC 326"): Measurement of Credit Losses on Financial Instruments requires entities to use a current lifetime expected credit loss methodology to measure impairments of certain financial assets. Using this methodology will result in earlier recognition of losses than under the current incurred loss approach, which requires waiting to recognize a loss until it is probable of having been incurred. There are other provisions within the standard that affect how impairments of other financial assets may be recorded and presented, and that expand disclosures. This standard will be effective for our interim and annual periods beginning with the first fiscal quarter of 2021, and must be applied on a modified retrospective basis.

New Accounting Pronouncements (Policies)

6 Months Ended

Mar. 27, 2020

New Accounting Pronouncements and Changes in Accounting Principles [Abstract]

The preparation of financial statements in conformity with U.S. GAAP requires us to employ estimates and make assumptions that affect the reported amounts of certain assets and liabilities, the revenues and expenses reported for the periods covered by the accompanying consolidated financial statements, and certain amounts disclosed in these Notes to the Consolidated Financial Statements. Although such estimates and assumptions are based on management’s most recent assessment of the underlying facts and circumstances utilizing the most current information available and past experience including considerations for potential impacts of the coronavirus (COVID-19) pandemic, actual results could differ significantly from those estimates and assumptions. Our estimates, judgments, and assumptions are evaluated periodically and adjusted accordingly. Please refer to Note 2- Significant Accounting Policies of Notes to Consolidated Financial Statements included in our 2019 Form 10-K for a discussion of other significant estimates and assumptions affecting our consolidated financial statements.

Fair Value and Fair Value Measurements

Certain amounts included in the accompanying consolidated financial statements are presented at “fair value.” Fair value is defined as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants as of the date fair value is determined (the “measurement date”). When determining fair value, we consider the principal or most advantageous market in which we would transact, and we consider only those assumptions we believe a typical market participant would consider when pricing an asset or liability. In measuring fair value, we use the following inputs in the order of priority indicated:

Level 1 - Quoted prices in active markets for identical assets or liabilities.

Level 2 - Observable inputs other than quoted prices in active markets included in Level 1, such as (i) quoted prices for similar assets or liabilities; (ii) quoted prices in markets that have insufficient volume or infrequent transactions (e.g., less active markets); and (iii) model-driven valuations in which all significant inputs are observable or can be derived principally from, or corroborated with, observable market data for substantially the full term of the asset or liability.

Level 3 - Unobservable inputs to the valuation methodology that are significant to the fair value measurement.

Please refer to Note 2- Significant Accounting Policies of Notes to Consolidated Financial Statements included in our 2019 Form 10-K for a more complete discussion of the various items within the consolidated financial statements measured at fair value and the methods used to determine fair value. Please also refer to Note 7- Sale of Energy, Chemicals and Resources for discussion regarding the Company's investment in Worley ordinary shares.

The net carrying amounts of cash and cash equivalents, trade receivables and payables and short-term debt approximate fair value due to the short-term nature of these instruments. See Note 12- Borrowings for a discussion of the fair value of long-term debt.

New Accounting Pronouncements

In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging ("ASC 815"): Targeted Improvements to Accounting for Hedging Activities. ASU 2017-12 provides financial reporting improvements related to hedging

relationships to better portray the economic results of an entity’s risk management activities in its financial statements. Additionally, ASU No. 2017-12 makes certain targeted improvements to simplify the application of the hedge accounting guidance. The revised guidance is effective for fiscal years beginning after December 15, 2018 with early adoption permitted. The updated guidance did not have a significant impact on the Company’s consolidated financial statements.

ASU 2017-04, Simplifying the Test for Goodwill Impairment, is effective for fiscal years beginning after December 15, 2019 with early adoption permitted. ASU 2017-04 removes the second step of the goodwill impairment test, which requires a hypothetical purchase price allocation. An entity will now recognize a goodwill impairment charge for the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the amount of goodwill allocated to the reporting unit. Management does not expect the adoption of ASU 2017-04 to have a material impact on the Company's financial position, results of operations or cash flows.

ASU No. 2016-13, Financial Instruments - Credit Losses ("ASC 326"): Measurement of Credit Losses on Financial Instruments requires entities to use a current lifetime expected credit loss methodology to measure impairments of certain financial assets. Using this methodology will result in earlier recognition of losses than under the current incurred loss approach, which requires waiting to recognize a loss until it is probable of having been incurred. There are other provisions within the standard that affect how impairments of other financial assets may be recorded and presented, and that expand disclosures. This standard will be effective for our interim and annual periods beginning with the first fiscal quarter of 2021, and must be applied on a modified retrospective basis.