Goodwill And Intangible Assets (Summary Of Intangible Assets Other Than Goodwill) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 37,230	$ 37,253
Less: Accumulated amortization	(29,003)	(28,711)
Net intangible assets other than goodwill	8,227	8,542
Beneficial Leases [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,836	28,860
Less: Accumulated amortization	(23,511)	(23,292)
Net intangible assets other than goodwill	5,325	5,568
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	7,255	7,254
Less: Accumulated amortization	(5,004)	(4,936)
Net intangible assets other than goodwill	2,251	2,318
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,139	1,139
Less: Accumulated amortization	(488)	(483)
Net intangible assets other than goodwill	$ 651	$ 656