Derivative Financial Instruments and Hedging Activities - Schedule of Effect of Derivatives As Hedges, Net of Applicable Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Accumulated Other Comprehensive Loss (Gain)		$ (1,288.0)	$ (1,301.3)	$ (1,360.1)
Amount of Loss (Gain) Recognized in Other Comprehensive Loss on Derivatives	$ (19.3)	26.6	78.0	105.9
Ending Accumulated Other Comprehensive Loss (Gain)	(1,046.1)	(1,234.2)	(1,046.1)	(1,234.2)
Unrealized Hedging (Losses) Gains
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Accumulated Other Comprehensive Loss (Gain)	178.0	70.0	79.0	(13.3)
Amount of Loss (Gain) Recognized in Other Comprehensive Loss on Derivatives	(19.3)	26.6	78.0	105.9
Amount of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss into Statement of Operations	9.3	1.1	11.0	5.1
Ending Accumulated Other Comprehensive Loss (Gain)	168.0	97.7	168.0	97.7
Amount of loss (gain) recognized, tax benefit (expense)	0.0	0.0	0.0	5.1
Amount of loss (gain) reclassified, tax benefit (expense)	(0.7)	(0.8)	(2.1)	(2.3)
Cash Flow Hedging \| Unrealized Hedging (Losses) Gains \| Interest rate hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Accumulated Other Comprehensive Loss (Gain)	178.0	70.0	79.0	(13.3)
Amount of Loss (Gain) Recognized in Other Comprehensive Loss on Derivatives	(19.3)	26.6	78.0	105.9
Amount of (Loss) Gain Reclassified from Accumulated Other Comprehensive Loss into Statement of Operations	9.3	1.1	11.0	5.1
Ending Accumulated Other Comprehensive Loss (Gain)	$ 168.0	$ 97.7	$ 168.0	$ 97.7

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss).

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Amount, after tax and before reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, after tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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