Income Taxes (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	$ 16		$ 16
Effective income tax rate	31.00%	34.00%	31.60%	33.70%
Research tax credits			29
Forecast
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Period Increase (Decrease)			80
Income Tax Expense Benefit, Period Increase (Decrease)			50
American Taxpayer Relief Act
Income Tax Contingency [Line Items]
Federal and foreign income tax expense	$ 6