Income Taxes (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Jan. 01, 2011
Unrecognized tax benefits interest related to unrecognized tax benefits
Balance at beginning of year	$ 285	$ 294
Additions for tax positions related to current year	8	7
Additions for tax positions of prior years	8	8
Reductions for tax positions of prior years	(7)	(17)
Reductions for expiration of statute of limitations		(5)
Reductions for settlements with tax authorities		(2)
Balance at end of year	$ 294	$ 285