Real Estate Investments - Base Rents (Details)	3 Months Ended
	Mar. 31, 2019 USD ($) lease item
Depreciation
Number of operating senior housing communities to a new operator | item	2
Write-off of straight-line rent	$ 1,926,000
Number of master leases with agreed upon cash rent | lease	4
Future minimum base rents receivable
2019	$ 101,223,000
2020	140,189,000
2021	131,128,000
2022	121,228,000
2023	124,492,000
Thereafter	$ 729,390,000