Consolidated Statements of Income (Stock-based Compensation Expense) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cost of revenue
Details of total stock-based compensation expense by statement functional line
Stock-based compensation expense	$ 22	$ 25	$ 27
Research and development
Details of total stock-based compensation expense by statement functional line
Stock-based compensation expense	304	363	368
Selling, general and administrative
Details of total stock-based compensation expense by statement functional line
Stock-based compensation expense	$ 111	$ 130	$ 148