Summary of Significant Accounting Policies - Narrative (Details)		3 Months Ended
	Jan. 01, 2020 USD ($)	Mar. 31, 2020 USD ($) segment	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Net assets		$ 6,135,169,000	$ 5,832,661,000
Net liabilities		$ 2,785,761,000	2,419,412,000
Number of segments | segment		1
Rent escalators adjustment period		1 year
Reserves for uncollectible amounts		$ 1,800,000	3,800,000
Accounts receivable		8,500,000	11,400,000
Reserve for losses		4,400,000	400,000
Deferred rental revenue receivables		89,100,000	84,000,000.0
Goodwill impairment		0
Provision for income taxes		0
Accounting Standards Update 2016-13
Summary Of Significant Accounting Policies [Line Items]
Recognition of loss due to adoption of new guidance	$ 300,000
Loans receivable and real estate assets held under direct financing lease	$ 40,300,000
Special Purpose Entity
Summary Of Significant Accounting Policies [Line Items]
Net assets		350,000,000	380,000,000
Net liabilities		$ 220,000,000	$ 230,000,000