Other Financial Information (Summary of Changes in Operating Working Capital) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts receivable	$ 12.4	$ (97.5)
Inventories	(30.3)	10.2
Prepaid expenses and other current assets	12.4	(4.6)
Accounts payable and accrued liabilities	(12.1)	91.4
Income taxes payable	40.8	0.0
Net (increase) decrease in noncash operating working capital	$ 23.2	$ (0.5)

The increase (decrease) during the reporting period in the amounts payable to vendors for goods and services received and the amount of obligations and expenses incurred but not paid.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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- Definition

The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.

+ References

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- Definition

The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

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- Definition

The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.

+ References

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- Definition

The increase (decrease) during the reporting period of all assets and liabilities used in operating activities.

+ References

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- Definition

Amount of increase (decrease) in prepaid expenses, and assets classified as other.

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- References

No definition available.

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