Property And Equipment (Summary Of Investment And Development Property) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Investment and development property	$ 80,086	$ 61,254
Land [Member]
Property, Plant and Equipment [Line Items]
Investment and development property	23,961	25,025
Building [Member]
Property, Plant and Equipment [Line Items]
Investment and development property	1,900	1,900
Construction-In-Progress (including capitalized interest) [Member]
Property, Plant and Equipment [Line Items]
Investment and development property	$ 54,225	$ 34,329