Total Equity - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Retained Earnings
Summary Of Changes In Equity [Line Items]
Acquisition and Surrender of Common Shares	$ 34.1	$ 20.9	$ 6.3	$ 34.1	$ 27.2