PROPERTY AND PROFESSIONAL AND GENERAL LIABILITY INSURANCE - Professional and General Liability Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Insurance coverage
Risk-free discount rate (as a percent)	2.25%	2.09%
Professional and General Liability Reserves
Insurance coverage
Self insurance reserve	$ 794	$ 755
Loss contingency discount rate, maturity rate period	7 years	7 years	7 years
Risk-free discount rate (as a percent)	2.25%	2.09%	1.97%
Professional and General Liability Reserves | Other operating expense, net
Insurance coverage
Malpractice expense	$ 281	$ 283	$ 232