PROPERTY AND PROFESSIONAL AND GENERAL LIABILITY INSURANCE - Professional and General Liability Reserves (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Other operating expense, net
Insurance coverage
Malpractice expense	$ 233	$ 202
Professional and General Liability Reserves
Insurance coverage
Self insurance reserve	$ 805		$ 755
Loss contingency discount rate, maturity rate period	7 years		7 years
Risk-free discount rate (as a percent)	1.42%		2.09%