Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) facility segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Accounting Policies [Abstract]
Accumulated amortization of deferred financing costs	$ 3,200,000	$ 4,200,000
Straight-line rental income	344,000	150,000	$ 0
Deferred straight-line rent receivable	500,000	200,000
Stock-based compensation expense	$ 2,416,000	1,546,000	1,522,000
Number of reportable segments | segment	1
Independent living facilities revenue	$ 3,228,000	2,970,000	$ 2,510,000
Restricted cash	$ 0	0
Accounting Policies [Line Items]
Number of living facilities | facility	188
Reserve on receivables		$ 0
Unpaid Base Rents
Accounting Policies [Line Items]
Reserve on receivables	$ 800,000
Other Tenant Receivables
Accounting Policies [Line Items]
Reserve on receivables	9,600,000
Lease Agreements
Accounting Policies [Line Items]
Remaining contractual payments as lessee	$ 300,000
Independent Living Facilities Owned and Operated by Company
Accounting Policies [Line Items]
Number of living facilities | facility	3