Financial Instruments and Fair Value Measurements - Derivative Financial Instruments (Details) - Designated as hedging instrument - Cash flow hedge - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional Amount	$ 1,173.4	$ 673.4
Fair Value - asset (liability)	(42.7)	(26.3)
Interest rate swap, maturity Sep 2021
Derivative [Line Items]
Notional Amount	$ 7.0	7.0
Strike (percent)	6.03%
Fair Value - asset (liability)	$ (0.3)	(0.2)
Interest rate swap, maturity Jun 2020
Derivative [Line Items]
Notional Amount	$ 250.0	250.0
Strike (percent)	1.72%
Fair Value - asset (liability)	$ (0.6)	(0.1)
Interest rate swap, maturity Mar 2024
Derivative [Line Items]
Notional Amount	$ 250.0	250.0
Strike (percent)	3.04%
Fair Value - asset (liability)	$ (25.3)	(14.7)
Cross-currency swap, maturity May 2034 1
Derivative [Line Items]
Notional Amount	41.6	41.6
Fair Value - asset (liability)	$ 6.9	(2.6)
Cross-currency swap, maturity May 2034 1 | GBP | Minimum
Derivative [Line Items]
Strike (percent)	4.82%
Cross-currency swap, maturity May 2034 1 | GBP | Maximum
Derivative [Line Items]
Strike (percent)	10.96%
Cross-currency swap, maturity May 2034 1 | USD
Derivative [Line Items]
Strike (percent)	9.80%
Cross-currency swap, maturity May 2034 2
Derivative [Line Items]
Notional Amount	$ 41.6	41.6
Fair Value - asset (liability)	$ 6.4	(2.6)
Cross-currency swap, maturity May 2034 2 | GBP | Minimum
Derivative [Line Items]
Strike (percent)	4.82%
Cross-currency swap, maturity May 2034 2 | GBP | Maximum
Derivative [Line Items]
Strike (percent)	10.96%
Cross-currency swap, maturity May 2034 2 | USD
Derivative [Line Items]
Strike (percent)	9.803%
Cross-currency swap, maturity May 2034 3
Derivative [Line Items]
Notional Amount	$ 41.6	41.6
Fair Value - asset (liability)	$ 6.0	(2.9)
Cross-currency swap, maturity May 2034 3 | GBP | Minimum
Derivative [Line Items]
Strike (percent)	4.82%
Cross-currency swap, maturity May 2034 3 | GBP | Maximum
Derivative [Line Items]
Strike (percent)	10.96%
Cross-currency swap, maturity May 2034 3 | USD
Derivative [Line Items]
Strike (percent)	9.745%
Cross-currency swap, maturity May 2034 4
Derivative [Line Items]
Notional Amount	$ 41.6	41.6
Fair Value - asset (liability)	$ 5.8	(3.2)
Cross-currency swap, maturity May 2034 4 | GBP | Minimum
Derivative [Line Items]
Strike (percent)	4.82%
Cross-currency swap, maturity May 2034 4 | GBP | Maximum
Derivative [Line Items]
Strike (percent)	10.96%
Cross-currency swap, maturity May 2034 4 | USD
Derivative [Line Items]
Strike (percent)	9.755%
Treasury rate lock, maturity Jun 2020 1
Derivative [Line Items]
Notional Amount	$ 75.0	0.0
Strike (percent)	1.63%
Fair Value - asset (liability)	$ (6.9)	0.0
Treasury rate lock, maturity Jun 2020 2
Derivative [Line Items]
Notional Amount	$ 75.0	0.0
Strike (percent)	1.63%
Fair Value - asset (liability)	$ (6.9)	0.0
Treasury rate lock, maturity Jun 2020 3
Derivative [Line Items]
Notional Amount	$ 100.0	0.0
Strike (percent)	1.64%
Fair Value - asset (liability)	$ (9.2)	0.0
Treasury rate lock, maturity Jun 2020 4
Derivative [Line Items]
Notional Amount	$ 100.0	0.0
Strike (percent)	1.57%
Fair Value - asset (liability)	$ (8.6)	0.0
Treasury rate lock, maturity Jun 2020 5
Derivative [Line Items]
Notional Amount	$ 150.0	0.0
Strike (percent)	1.37%
Fair Value - asset (liability)	$ (10.0)	$ 0.0