Consolidated cash flow statements (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Consolidated cash flow statements [Abstract]
Proceeds from investments in contracted concessional assets	$ 72.6	$ 42.5
Purchase of investments in contracted concessional assets	$ 4.6	$ 12.4

The cash inflow from sales of property, plant and equipment, classified as investing activities. [Refer: Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2018-01-01
-Paragraph 16
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_16_b&doctype=Standard
-URIDate 2018-03-16

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