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Business Acquisitions, Goodwill and Intangible Assets - Goodwill (Details) $ in Thousands	9 Months Ended
	Jun. 30, 2017 USD ($)
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	$ 5,823,843
Acquired	3,800
Disposed	(1,800)
Foreign Exchange Impact	14,700
Goodwill at the end of the period	5,840,508
DCS
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	3,198,200
Acquired	3,800
Disposed	(1,800)
Foreign Exchange Impact	7,500
Goodwill at the end of the period	3,207,700
CS
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	915,200
Foreign Exchange Impact	3,000
Goodwill at the end of the period	918,200
MS
Changes in the carrying value of goodwill by reporting segment
Goodwill at the beginning of the period	1,710,400
Foreign Exchange Impact	4,200
Goodwill at the end of the period	$ 1,714,600

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
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-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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