Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) lease	Sep. 30, 2019 USD ($) lease
Leases [Abstract]
Number of new ground leases commenced \| lease			1	1
Rental and other revenues from operating lease payments	$ 186.3	$ 173.1	$ 546.8	$ 511.5
Variable lease payments	$ 42.7	$ 39.1	$ 127.3	$ 115.2

Amount of variable lease payments from operating, direct financing, and sales-type leases, excluding amount included in measurement of lease receivable.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919372-209981

Name:	us-gaap_VariableLeaseIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration