VARIABLE INTEREST ENTITIES - Consolidated VIEs (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
ASSETS (LIABILITIES)
Accounts receivable and other	$ 35	$ 35
Inventories	7	7
Equity investments	1,047	965
Plant, property and equipment	1,913	1,949
Other assets		1
Accounts payable and accrued liabilities	(26)	(32)
Accounts payable to affiliates	(5)	(5)
Accrued interest	(9)	(8)
Current portion of long-term debt	(15)	(14)
Long-term debt	(1,938)	(1,889)
Other liabilities	(29)	(27)
Consolidated VIEs | Restricted VIEs
ASSETS (LIABILITIES)
Accounts receivable and other	21	25
Inventories	6	6
Equity investments	1,047	965
Plant, property and equipment	859	872
Other assets	2	2
Accounts payable and accrued liabilities	(18)	(26)
Accounts payable to affiliates	(18)	(6)
Accrued interest	(1)	(1)
Current portion of long-term debt	(15)	(14)
Long-term debt	(325)	(326)
Other liabilities	$ (25)	$ (24)