EQUITY - Changes in Shareholders' Equity (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Changes in Shareholders' Equity
Balances			$ 958	$ 785
Net income (loss)			(17)	(10)
Distributions paid to noncontrolling interests			(82)	(35)
Contributions from noncontrolling interests				2
Other comprehensive income (loss)	$ 3	$ 4	(36)	9
Purchases (sales) of businesses and noncontrolling interests			76	212
Purchase accounting adjustments			237
Stock-based compensation expense and issuance of common stock			29	55
Balances	1,165	1,018	1,165	1,018
Common Stock
Changes in Shareholders' Equity
Balances			$ 7	$ 7
Balances (in shares)			98,495	98,382
Stock-based compensation expense and issuance of common stock (in shares)			1,033	1,210
Balances	$ 7	$ 7	$ 7	$ 7
Balances (in shares)	99,528	99,592	99,528	99,592
Additional Paid-in Capital
Changes in Shareholders' Equity
Balances			$ 4,815	$ 4,614
Purchases (sales) of businesses and noncontrolling interests			(43)	130
Stock-based compensation expense and issuance of common stock			29	54
Balances	$ 4,801	$ 4,798	4,801	4,798
Accumulated Other Comprehensive Loss
Changes in Shareholders' Equity
Balances			(164)	(182)
Other comprehensive income (loss)			(36)	9
Balances	(200)	(173)	(200)	(173)
Accumulated Deficit
Changes in Shareholders' Equity
Balances			(1,550)	(1,410)
Net income (loss)			(113)	(43)
Balances	(1,663)	(1,453)	(1,663)	(1,453)
Treasury Stock
Changes in Shareholders' Equity
Balances			(2,417)	(2,378)
Stock-based compensation expense and issuance of common stock				1
Balances	(2,417)	(2,377)	(2,417)	(2,377)
Noncontrolling Interests
Changes in Shareholders' Equity
Balances			267	134
Net income (loss)			96	33
Distributions paid to noncontrolling interests			(82)	(35)
Contributions from noncontrolling interests				2
Purchases (sales) of businesses and noncontrolling interests			119	82
Purchase accounting adjustments			237
Balances	$ 637	$ 216	$ 637	$ 216