Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016	Dec. 31, 2016
Investments
Unrealized gains (losses) on trading securities	$ 38	$ 5
Trading securities
Investments
Amortized Cost	1,208		$ 1,236
Fair Value	1,286		1,277
Domestic equity securities
Investments
Amortized Cost	529		444
Fair Value	589		482
Domestic debt securities held in mutual funds/ETFs/U.S. Treasuries
Investments
Amortized Cost	300		437
Fair Value	301		437
Foreign equity securities
Investments
Amortized Cost	236		198
Fair Value	252		199
High yield securities
Investments
Amortized Cost	96		114
Fair Value	96		115
Collateralized loan obligation
Investments
Amortized Cost	18		25
Fair Value	19		26
Money market funds held in trading accounts
Investments
Amortized Cost	26		13
Fair Value	26		13
Other trading investments
Investments
Amortized Cost	3		5
Fair Value	3		5
Denominated in foreign currencies | Money market funds
Investments
Fair Value			1
Denominated in foreign currencies | Money market funds | Maximum
Investments
Fair Value	4
Denominated in foreign currencies | Foreign equity securities
Investments
Fair Value	97		91
Denominated in Euros | Foreign equity securities
Investments
Fair Value	39		35
Denominated in Japanese Yen | Foreign equity securities
Investments
Fair Value	22		20
Denominated in British pounds | Foreign equity securities
Investments
Fair Value	17		16
Denominated in Swiss Franc | Foreign equity securities
Investments
Fair Value	6		6
Denominated in other foreign currencies | Foreign equity securities
Investments
Fair Value	$ 13		$ 14