Income Taxes (Schedule Of Reconciliation Of U.S. Federal Statutory Tax Rate To Our Effective Income Tax Rate) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014
Income Tax Disclosure [Abstract]
U.S. federal statutory tax				35.00%	35.00%	35.00%
Research and development credits (1)				(2.90%)	(4.90%)	0.80%
Amendments to the R&E regulations (2)					(3.40%)
Tax basis adjustment (3)				(3.60%)
Tax on international activities				(0.20%)	(0.10%)	(1.20%)
Tax deductible dividends				(0.70%)	(0.60%)	(0.70%)
State income tax provision, net of effect on U.S. federal tax				0.70%	0.40%	0.80%
Federal audit settlements (4)				(3.60%)
Other provision adjustments				(1.00%)		(0.70%)
Effective income tax rate				23.70%	26.40%	34.00%
Tax Adjustments, Settlements, and Unusual Provisions	$ (188)	$ (212)	$ (145)
Tax Basis Restoration [Member]
Income Tax Disclosure [Abstract]
Tax Adjustments, Settlements, and Unusual Provisions							(265)
2009-2010 Federal Tax Audit Settlement [Member]
Income Tax Disclosure [Abstract]
Tax Adjustments, Settlements, and Unusual Provisions							(143)
2007-2008 Federal Tax Audit Settlement [Member]
Income Tax Disclosure [Abstract]
Tax Adjustments, Settlements, and Unusual Provisions							$ (116)