VARIABLE INTEREST ENTITIES (VIEs) - Consolidated VIEs (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
ASSETS (LIABILITIES)
Cash and cash equivalents	$ 83	$ 33
Accounts receivable and other	43	48
Inventories	10	8
Other current assets	6	8
Equity investments	1,098	1,196
Property, plant and equipment	1,528	1,529
Other assets		6
Accounts payable and accrued liabilities	(28)	(36)
Accounts payable to affiliates, net	(8)	(6)
Accrued interest	(11)	(12)
Current portion of long-term debt	(123)	(36)
Long-term debt	(1,880)	(2,072)
Other liabilities	(36)	(29)
Restricted VIEs | Consolidated VIEs
ASSETS (LIABILITIES)
Cash and cash equivalents		16
Accounts receivable and other		39
Inventories		8
Other current assets		6
Equity investments	$ 491	1,196
Property, plant and equipment		1,240
Other assets		1
Accounts payable and accrued liabilities		(33)
Accounts payable to affiliates, net		(40)
Accrued interest		(2)
Current portion of long-term debt		(36)
Long-term debt		(341)
Other liabilities		(27)
Deferred state income tax		$ (9)