Asset Acquisitions and Dispositions - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($) loan property	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($) property loan
Real Estate [Line Items]
Cash paid in acquisition of real estate			$ 543	$ 11,124
Number of real estate properties sold | property	37	126	149	862
Proceeds from dispositions of real estate			$ 25,424	$ 169,457
Proceeds from sale and resolution of mortgage loans		$ 200		$ 1,800
Nonperforming financing receivable | Residential mortgage | Loans receivable
Real Estate [Line Items]
Number of mortgage loans resolved | loan		5		18
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Real Estate [Line Items]
Proceeds from dispositions of real estate	$ 5,000	$ 22,600	$ 23,800	$ 175,800
SFR Properties
Real Estate [Line Items]
Number of real estate properties directly acquired | property	0	28	4	85
Cash paid in acquisition of real estate		$ 3,800	$ 500	$ 11,100