The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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The amount of net gains or losses on interest rate cash flow hedges reclassified during the period to earnings from accumulated other comprehensive income upon the hedged transaction affecting earnings.

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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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Financial Instruments - (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Financial Instruments - (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Interest rate cap, fair value	$ 1.0		$ 1.0		$ 1.0
Unrealized (loss) gain from hedge accounting	0.4	$ 0.4	0.6	$ 12.8
Interest Rate Cap
Derivative [Line Items]
Notional amount	2,800.0		2,800.0		2,800.0
Interest Rate Cap Agreement Maturity Date December 31, 2020
Derivative [Line Items]
Notional amount	1,400.0		1,400.0
Interest Rate Cap Agreement Maturity Date December 31, 2022
Derivative [Line Items]
Notional amount					$ 1,400.0
Interest Rate Contract
Derivative [Line Items]
Unrealized (loss) gain from hedge accounting	(0.4)	(0.4)	(0.6)	(12.8)
Amount expected to be reclassified from AOCL to interest expense in next twelve months			5.0
Derivative
Derivative [Line Items]
Interest income (expense) reclassified into earnings	$ 1.6	$ 0.3	$ 4.1	$ 2.0