VARIABLE INTEREST ENTITIES - Consolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
ASSETS (LIABILITIES)
Accounts receivable and other	$ 36	$ 35
Inventories	7	7
Equity investments	1,083	965
Plant, property and equipment	1,928	1,949
Other assets		1
Accounts payable and accrued liabilities	(24)	(32)
Accounts payable to affiliates	(4)	(5)
Accrued interest	(13)	(8)
Current portion of long-term debt	(14)	(14)
Long-term debt	(2,059)	(1,889)
Other liabilities	(28)	(27)
Consolidated VIEs | Restricted VIEs
ASSETS (LIABILITIES)
Accounts receivable and other	22	25
Inventories	6	6
Equity investments	1,083	965
Plant, property and equipment	864	872
Other assets	2	2
Accounts payable and accrued liabilities	(15)	(26)
Accounts payable to affiliates	(7)	(6)
Accrued interest	(5)	(1)
Current portion of long-term debt	(14)	(14)
Long-term debt	(326)	(326)
Other liabilities	$ (24)	$ (24)