EQUITY COMPENSATION PLANS - Stock Options (Details) - Stock Options - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock incentive and option plans
Stock option expiration period	10 years
Stock option vesting period	3 years
SHARES
Outstanding, beginning of year (in shares)	11,380,013	11,910,501	12,378,372
Granted (in shares)	1,202,314	1,491,893	1,679,941
Exercised (in shares)	(1,942,192)	(1,951,920)	(2,061,553)
Canceled (in shares)	(123,502)	(70,461)	(86,259)
Outstanding, end of year (in shares)	10,516,633	11,380,013	11,910,501
Exercisable, end of year (in shares)	7,993,297	8,371,809	8,720,943
Vested and expected to vest, end of year (in shares)	10,365,162
AVERAGE PRICE PER SHARE
Outstanding, beginning of year (in dollars per share)	$ 95.76	$ 84.22	$ 74.23
Granted (in dollars per share)	158.23	136.87	117.60
Exercised (in dollars per share)	64.63	56.00	50.33
Canceled (in dollars per share)	127.02	116.44	111.08
Outstanding, end of year (in dollars per share)	108.28	95.76	84.22
Exercisable, end of year (in dollars per share)	97.13	$ 84.40	$ 72.35
Vested and expected to vest, end of year (in dollars per shares)	$ 107.77
Total intrinsic value of options exercised during period	$ 161	$ 142	$ 140
Total aggregate intrinsic value of in-the-money options outstanding	$ 397
Weighted-average remaining contractual life of options outstanding	6 years 4 months 24 days
Total aggregate intrinsic value of in-the-money options exercisable	$ 391
Weighted-average remaining contractual life of options exercisable	5 years 6 months
Aggregate intrinsic value of vested and expected to vest options outstanding	$ 397
Weighted-average remaining contractual life of vested and expected to vest options outstanding	6 years 4 months 24 days