Financial Instruments and Fair Value Measurements - Schedule of Long-term Debt Carrying Value and Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
4.00% Senior Notes
Debt Instrument [Line Items]
Interest rate (as a percentage)	4.00%
Carrying Value
Debt Instrument [Line Items]
Debt, fair value	$ 638.1	$ 40.7
Carrying Value | Real estate related
Debt Instrument [Line Items]
Debt, fair value	88.1	40.7
Fair Value
Debt Instrument [Line Items]
Debt, fair value	620.0	41.1
Fair Value | Real estate related
Debt Instrument [Line Items]
Debt, fair value	$ 80.4	41.1
Senior Notes | 4.00% Senior Notes
Debt Instrument [Line Items]
Interest rate (as a percentage)	4.00%
Senior Notes | Carrying Value | 4.00% Senior Notes
Debt Instrument [Line Items]
Debt, fair value	$ 550.0	0.0
Senior Notes | Fair Value | 4.00% Senior Notes
Debt Instrument [Line Items]
Debt, fair value	$ 539.6	$ 0.0