Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2018	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 302,543		$ 308,995
Real estate, net	$ 754,324		780,814
Cash and cash equivalent maturity maximum	3 months
Percentage of cash mortgage collateralized	100.00%
Allowance for doubtful accounts	$ 1,501		$ 1,473
Accounting Standards Update 2016-01
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ 5,156