Real Estate and Other Activities - Summary of Operating Results from Properties Sold (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022
Disposal Group, Not Discontinued Operations [Member]
Straight-line rent write-offs	$ 1.8	$ 6.3
Massachusetts-based General Acute Care Hospitals [Member]
Straight-line rent write-offs	125.0	125.0
Massachusetts-based General Acute Care Hospitals [Member] | Disposal Group, Not Discontinued Operations [Member]
Gains	$ 16.4	$ 468.0