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STOCK INCENTIVE PLANS - Restricted Stock Units (Details) - Restricted Stock Units [Member] $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio	1
Fair value of shares vested | $	$ 22	$ 21	$ 21
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Outstanding at beginning of period (in shares) | shares	352,919	373,403	432,783
Issued (in shares) | shares	141,775	129,378	113,909
Canceled (in shares) | shares	(56,393)	(47,488)	(62,869)
Vested (in shares) | shares	(94,487)	(102,374)	(110,420)
Outstanding at end of period (in shares) | shares	343,814	352,919	373,403
Weighted Average Price Per Share [Abstract]
Outstanding at beginning of period, weighted average price per share (in dollars per share) | $ / shares	$ 226.31	$ 221.77	$ 213.45
Issued, weighted average price per share (in dollars per share) | $ / shares	284.98	222.53	230.36
Cancelled, weighted average price per share (in dollars per share) | $ / shares	245.08	229.36	229.70
Vested, weighted average price per share (in dollars per share) | $ / shares	233.75	203.51	193.51
Outstanding at end of period, weighted average price per share (in dollars per share) | $ / shares	$ 245.38	$ 226.31	$ 221.77
Unearned unrecognized compensation | $	$ 51
Weighted average period to recognize (in years)	3 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	7 years

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Unrecognized cost of unvested share-based compensation awards.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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