Summary Of Significant Accounting Policies (Goodwill) (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Percentage of the discounted cash flow method for estimation of fair value of reporting units	80.00%
Percentage of the public company guideline method for estimation of fair value of reporting units	20.00%
Goodwill, Impaired, Accumulated Impairment Loss	$ 1,748,200	$ 1,417,700
Reduction in value of goodwill	$ 330,500	$ 1,326,701