Subsequent Events - Mortgage Loan Agreements (Details) $ in Thousands	1 Months Ended	3 Months Ended
	May 03, 2018 USD ($) property	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Subsequent Event [Line Items]
Gain (loss) on extinguishment and forgiveness of debt, net		$ 0	$ (70)
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of properties secured by mortgage loan | property	1
Mortgage loan foreclosure, outstanding balance	$ 16,200
Gain (loss) on extinguishment and forgiveness of debt, net	$ 5,200