Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
U.S. government:
Amounts billed	$ 64.3	$ 137.8
Costs and profits not billed	233.4	137.9
Contract receivables	297.7	275.7
Other trade receivables	890.7	985.4
Finance receivables	13.9	5.8
Notes receivable	24.8	34.2
Other receivables	43.0	46.3
Receivables, gross	1,270.1	1,347.4
Less allowance for doubtful accounts	(14.5)	(18.3)	$ (20.2)	$ (21.2)
Receivables, net	1,255.6	1,329.1
Classification of receivables
Current receivables	1,229.4	1,306.3
Long-term receivables (included in “Other long-term assets”)	$ 26.2	$ 22.8

-- None. No documentation exists for this element. --

No definition available.

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- Definition

Represents the other trade receivables not elsewhere specified in the taxonomy.

+ References

No definition available.

+ Details

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- Definition

Represents the gross receivables of the entity, which may include trade receivables, finance receivables, notes receivables and other receivables before the allowance for doubtful accounts.

+ References

No definition available.

+ Details

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- Definition

Represents the gross receivables of the entity, which may include trade receivables, finance receivables, notes receivables and other receivables net of allowance for doubtful accounts.

+ References

No definition available.

+ Details

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- Definition

For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amounts due for billed services rendered or to be rendered, actions taken or to be taken, or a promise to refrain from taking certain actions in accordance with the terms of a legally binding agreement between the Company and, at a minimum, one other party. An example would be amounts billed to customers under contracts or programs but not paid as of the balance sheet date.

+ References

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- References

No definition available.

+ Details

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- Definition

The amount of receivables that are derived from government contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 310
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68054760&loc=d3e55295-109406

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- Definition

Unbilled amounts (net of unliquidated progress payments) of government contract receivables.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The aggregate of amounts due from customers or clients more than one year from the balance sheet date, for goods or services that have been delivered or sold in the normal course of business and an amount representing an agreement for an unconditional promise by the maker to pay the Company (holder) a definite sum of money at a future date more than one year from the balance sheet date, reduced to their estimated net realizable fair value by an allowance established by the Company of the amount it deems uncertain of collection and net of any write-downs taken for collection uncertainty on the part of the holder, respectively.

+ References

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- Definition

Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(3))
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- Definition

Net amount of the investment in a contractual right to receive money on demand or on fixed or determinable dates that is recognized as an asset in the creditor's statement of financial position. Examples include, but are not limited to, credit card receivables, notes receivable and receivables relating to lessor's rights to payments from leases other than operating leases that have been recorded as assets. Excludes trade accounts receivable with contractual maturity of one year or less and arose from the sale of goods or services.

+ References

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- Definition

Amount due from parties in nontrade transactions, classified as other.

+ References

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- Definition

The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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