Income Taxes - Income Taxes Refundable and Payable (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Income taxes refundable	$ 88.7	$ 169.0
Income taxes payable	(64.5)	(78.4)
Net income taxes refundable	$ 24.2	$ 90.6	$ 72.2

The excess of amount paid for current tax in respect of current and prior periods over the amount due for those periods. Current tax is the amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 54
-Subparagraph n
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_n&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_CurrentTaxAssets
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant