Domestic And Foreign Income Taxes (Schedule Of Reconciliation Of The Statutory Federal Income Tax Rate To The Effective Tax Rate Based On Income (Loss)) (Details)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	[1]	Dec. 31, 2017
Domestic And Foreign Income Taxes [Abstract]
Tax provision at statutory rate		21.00%	21.00%		34.00%	[1]
Change in valuation allowance		(23.61%)	43.36%		(247.26%)	[1]
Impact of permanent items, including stock based compensation expense and impairment loss		(0.27%)	(52.73%)		5.25%	[1]
Effect of foreign tax rates		0.34%	0.51%		(4.44%)	[1]
State taxes net of federal benefit		(1.00%)	0.14%		3.11%	[1]
Effect of dividend of foreign subsidiary in prior year					35.18%	[1]
Prior year provision to return true-up		(5.82%)	(5.61%)		19.47%	[1]
Non-controlling interest		(0.66%)	0.16%		0.98%	[1]
Change in expected future rate	[1]				156.54%
Other		(0.77%)	(0.15%)		(2.51%)	[1]
Domestic and foreign income tax rate		(10.79%)	6.68%		0.32%	[1]

[1] Historical effective tax rates have been adjusted due to discontinued operations. Please refer to Note 2 for further information.