Related Party Transactions (Summary of Related Party Transactions) (Details) - Affiliated Entity - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Tax, utility, insurance and other reimbursement	$ 796	$ 878	$ 589
Rent expense	1,014	1,014	1,014
Capital assets acquired	561	323	261
Total	$ 2,371	$ 2,215	$ 1,864