Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Jan. 01, 2017
Current assets:
Allowances for doubtful accounts	$ 291	$ 252
Shareholders' equity:
Preferred par value	$ 0	$ 0
Preferred stock, shares authorized (in shares)	2,000,000	2,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value per share (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	4,320,000,000	4,320,000,000
Common stock, shares issued (in shares)	3,119,843,000	3,119,843,000
Treasury stock, shares	437,318,000	413,332,000