Share-Based Associate Compensation Plans (Stock Option Information) (Details) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares
Shares
Outstanding at beginning of year (in shares) | shares	3,012
Granted (in shares) | shares	706
Exercised (in shares) | shares	(527)
Forfeited or expired (in shares) | shares	(125)
Outstanding at end of year (in shares) | shares	3,066
Options exercisable at end of period (in shares) | shares	2,072
Weighted-average exercise price
Outstanding at beginning of year (in dollars per share) | $ / shares	$ 42.12
Granted (in dollars per share) | $ / shares	70.70
Exercised (in dollars per share) | $ / shares	38.33
Forfeited or expired (in dollars per share) | $ / shares	47.07
Outstanding at end of year (in dollars per share) | $ / shares	49.14
Options exercisable at end of period (in dollars per share) | $ / shares	$ 40.69
Aggregate intrinsic value
Outstanding at end of year | $	$ 79
Options exercisable at end of period | $	$ 71
Weighted-average remaining contractual life
Outstanding option shares at December 31, 2017	5 years 221 days
Options exercisable at end of period	4 years 47 days