Summary Of Significant Accounting Policies (Reconciliation of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Abstract]
Cash and cash equivalents	$ 42,046	$ 37,379	$ 7,214	$ 114,882
Restricted cash included in - Land and building held for development	1,088	1,088	1,088	1,088
Cash, cash equivalents and restricted cash at the end of the period	$ 43,134	$ 38,467	$ 8,302	$ 115,970