EQUITY - Changes in Shareholders' Equity - Noncontrolling interests (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Changes in Shareholders' Equity
Balance	$ 1,165	$ 1,018	$ 958	$ 785
Net income (loss)	(17)	(10)
Noncontrolling Interests
Changes in Shareholders' Equity
Balance	637	216	$ 267	$ 134
Net income (loss)	96	33
Noncontrolling Interests | Hospital operations and other
Changes in Shareholders' Equity
Balance	99	37
Net income (loss)	8	21
Noncontrolling Interests | Ambulatory Care
Changes in Shareholders' Equity
Balance	538	179
Net income (loss)	$ 88	$ 12