Derivative Instruments and Hedging Activities - Gains and losses on derivatives (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Gains and losses on derivatives
Tax impact	$ (1.0)	$ 1.7	$ (0.1)	$ 4.8
Gain (loss) reclassified from AOCL into income, net	(3.3)	8.5	(0.3)	11.6
Interest expense
Gains and losses on derivatives
Gain (loss) recorded in AOCL on derivatives, before tax	4.3	$ (10.2)	0.4	$ (16.4)
Interest rate swaps \| Hedging \| Cash flow hedging
Gains and losses on derivatives
Losses on derivative	$ 5.8		$ 9.6

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Amount of decrease in the fair value of derivatives recognized in the income statement.

+ References

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

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Amount, before reclassification, of tax expense (benefit) for 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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