Summary Of Significant Accounting Policies (Accounting Changes To Consolidated Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)	$ (22,887)	$ (5,956)	$ 2,294	$ (2,140)	$ (28,843)	$ 154
Change in net deferred tax assets						(69)
Accounts payable and accrued expenses					1,300	(3,282)
Net cash provided by operating activities					$ (23,126)	3,058
Tax Year 2019 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)			2,294			154
Change in net deferred tax assets						(69)
Accounts payable and accrued expenses						(3,282)
Net cash provided by operating activities						3,058
Tax Year 2019 [Member] | As Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)			2,357			260
Change in net deferred tax assets						(30)
Accounts payable and accrued expenses						(3,427)
Net cash provided by operating activities						3,058
Tax Year 2019 [Member] | Adjustments [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)			$ (63)			(106)
Change in net deferred tax assets						(39)
Accounts payable and accrued expenses						$ 145