Real Estate Investments, Net (Geographic Concentrations) (Details) - property	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Mar. 31, 2019
Geographic Concentration Risk | Sales Revenue, Net | Florida (1)
Concentration Risk [Line Items]
Concentration risk, percentage	25.20%	16.60%	17.50%
Geographic Concentration Risk | Sales Revenue, Net | Georgia
Concentration Risk [Line Items]
Concentration risk, percentage		10.10%	10.70%
Geographic Concentration Risk | Sales Revenue, Net | Michigan (2)
Concentration Risk [Line Items]
Concentration risk, percentage	10.90%	13.10%	11.60%
Geographic Concentration Risk | Sales Revenue, Net | Pennsylvania
Concentration Risk [Line Items]
Concentration risk, percentage		10.20%	10.80%
Held-for-sale | Florida (1)
Concentration Risk [Line Items]
Number of properties held for sale	3
Seniors Housing Communities | Held-for-sale
Concentration Risk [Line Items]
Number of properties held for sale	14			1
Seniors Housing Communities | Held-for-sale | Florida (1)
Concentration Risk [Line Items]
Number of properties held for sale	2
Seniors Housing Communities | Held-for-sale | Michigan (2)
Concentration Risk [Line Items]
Number of properties held for sale	14