Income Taxes (Reconciliation Of Effective Tax Rate, By Percentage) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Abstract]
Tax at U.S. statutory rate	35.00%	35.00%	35.00%
Surtax exemption	(0.60%)	(1.10%)	(0.70%)
State income taxes, net of federal benefit	0.20%	0.60%	1.00%
Foreign income taxes, net of foreign tax credits	(7.20%)	(3.60%)	7.80%
Other nondeductible items	(0.90%)	0.00%	3.10%
Effect of (decrease) increase in uncertain tax positions	0.00%	(1.40%)	(10.20%)
Federal credits		15.10%
Change in valuation allowance	(30.10%)	(35.20%)
Other	0.30%	(2.20%)	2.30%
Effective tax rate	(3.30%)	7.20%	38.30%