Subsequent Events (Details) $ in Millions				3 Months Ended
	Apr. 26, 2019 USD ($) ft²	Apr. 04, 2019 USD ($) ft² shares	Apr. 03, 2019 USD ($) ft²	Mar. 31, 2019 ft² shares	Apr. 30, 2019 shares	Apr. 16, 2019 USD ($)	Dec. 31, 2018 shares
Subsequent Event [Line Items]
Square feet of healthcare properties | ft²				52,943
Common stock, shares authorized (in shares) | shares				500,000,000			500,000,000
Subsequent Event
Subsequent Event [Line Items]
Asset acquisition, consideration transferred		$ 14.8
Number of units issued for funding purchase price (in shares) | shares		346,989
Business acquisition, equity interest issued or issuable, value assigned		$ 6.5
Size of property | ft²		27,035
Leased percentage		100.00%
Yield on investment percentage		6.00%
Common stock, additional shares authorized (in shares) | shares					4,550,000
Common stock, shares authorized (in shares) | shares					7,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Subsequent Event
Subsequent Event [Line Items]
Square feet of healthcare properties | ft²	49,443		3,500
Proceeds from divestiture of business	$ 11.5		$ 1.0
Disposal group, not discontinued operation, gain (loss) on disposal	$ 2.9		$ 0.2
Disposal group, not discontinued operation, cap rate	6.30%		7.40%
Mezzanine Loan | Subsequent Event
Subsequent Event [Line Items]
Debt instrument, face amount						$ 0.9
Weighted average interest rate						9.00%
Percentage of borrower's ownership interests, real estate owner						100.00%