Restructuring and Relocation Activities - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Mar. 31, 2017
Restructuring Cost And Reserve [Line Items]
Restructuring expected accrual to pay		$ 35.1
Restructuring expected accrual remaining to pay		$ 1.6
Scenario, Forecast [Member] \| Fusion Program \| Building Cost Of Charlotte Campus
Restructuring Cost And Reserve [Line Items]
Total estimated net cash cost	$ 120.0

Amount expected to be recognized in earnings for the specified restructuring cost.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Name:	us-gaap_RestructuringAndRelatedCostExpectedCost1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant