Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income tax (expense)/benefit on unrealized gains (losses) related to derivative activity	$ 0.0	$ (0.1)	$ 0.0	$ 0.1
Income tax (expense)/benefit on reclassification of earnings related to derivative activity	0.0	(0.1)	0.1	0.0
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives Related to Discontinued Operations, Tax	0.0	(0.4)	0.0	(0.4)
Income tax (expense)/benefit on reclassification of earnings related to pension and postretirement activity	0.0	(0.1)	(0.1)	(0.1)
Subsidiaries [Member]
Income tax (expense)/benefit on unrealized gains (losses) related to derivative activity	0.0	0.0	0.0	0.2
Income tax (expense)/benefit on reclassification of earnings related to derivative activity	(0.1)	0.0	(0.1)	0.0
Income tax (expense)/benefit on reclassification of earnings related to pension and postretirement activity	$ (0.2)	$ 0.9	$ (0.6)	$ (0.5)

Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives Related to Discontinued Operations, Tax

No definition available.

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- Definition

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

+ References

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- Definition

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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- Definition

Amount of tax expense (benefit), before reclassification adjustments, related to increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e640-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669646-108580

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