Summary of Significant Accounting Policies (Narrative) (Details)		12 Months Ended
	Jan. 01, 2019 USD ($) property lease	Dec. 31, 2019 USD ($) property segment lease	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Sep. 30, 2019 USD ($)
Schedule of Shares Repurchased [Line Items]
Overstatement of previously recorded tax benefits, deferred tax assets and net income			$ 800,000	$ 300,000	$ 200,000
Remaining lease term		5 years 7 months 6 days
Operating lease impairment loss		$ 6,500,000
Bad debt expense		6,464,000	14,797,000	$ 12,413,000
Assets held for sale		$ 70,839,000	$ 52,397,000
Number of reportable segments | segment		3	3	3
Money market funds		$ 0	$ 0
Cash and cash equivalents		95,691,000	77,264,000	$ 94,177,000
Cash in excess of FDIC limit		$ 73,200,000	58,900,000
Number of senior housing communities | property		59
Deferred tax asset, net		$ 3,900,000	4,100,000
Valuation allowance		$ 0	$ 0
Effective income tax rate		26.40%	26.60%
Number of operating lease contracts | lease	11	8
Operating lease right-of-use assets		$ 14,351,000
Operating lease liabilities		9,133,000				$ 9,133,000
Operating lease costs		1,000,000.0
Present value of lease payments		$ 4,800,000
Minimum
Schedule of Shares Repurchased [Line Items]
Lease intangibles, lease-up period		6 months
Maximum
Schedule of Shares Repurchased [Line Items]
Lease intangibles, lease-up period		24 months
Building
Schedule of Shares Repurchased [Line Items]
Useful life		40 years
Land Improvements
Schedule of Shares Repurchased [Line Items]
Useful life		15 years
Fixtures and improvements | Minimum
Schedule of Shares Repurchased [Line Items]
Useful life		7 years
Fixtures and improvements | Maximum
Schedule of Shares Repurchased [Line Items]
Useful life		10 years
Land and Building
Schedule of Shares Repurchased [Line Items]
Number of operating lease contracts | property	17
Accounting Standards Update 2016-02
Schedule of Shares Repurchased [Line Items]
Written off accounts receivable	$ 100,000
Straight-line rents receivable	100,000
Operating lease right-of-use assets	10,200,000
Operating lease liabilities	10,200,000
Operating lease costs	$ 500,000
Seniors Housing Communities
Schedule of Shares Repurchased [Line Items]
Ancillary revenue		$ 15,400,000	$ 8,100,000	$ 800,000