Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Disclosure Of Finance Lease And Operating Lease By Lessee [Abstract]
Rental expense for operating leases	$ 82	$ 73	$ 55
Operating lease arrangements period	10 years

The portion of operating lease payments that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with any amounts guaranteed by the lessee or by a party related to the lessee recognised as an expense.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2017-01-01
-Paragraph 35
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2017-03-02&anchor=para_35_c&doctype=Standard&book=B
-URIDate 2017-03-09

Name:	ifrs-full_MinimumOperatingLeasePayments
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration