Schedule of Goodwill Carrying Value Rollfoward (Details 4) - USD ($) $ in Thousands	6 Months Ended
Sep. 30, 2017	Mar. 31, 2017
Goodwill Gross Value [Member]
Goodwill
Goodwill, Gross	$ 3,093,251	$ 3,086,789
Impact of excess tax basis amortization	(10,407)
Other, including changes in foreign exchange rates	16,869
Goodwill Accumulated Impairment [Member]
Goodwill
Goodwill, Impaired, Accumulated Impairment Loss	(1,161,900)	(1,161,900)
Impact of excess tax basis amortization	0
Other, including changes in foreign exchange rates	0
Goodwill Net Value [Member]
Goodwill
Goodwill	1,931,351	$ 1,924,889
Impact of excess tax basis amortization	(10,407)
Other, including changes in foreign exchange rates	$ 16,869

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.

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)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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