ACCOUNTS RECEIVABLE AND OTHER (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
ACCOUNTS RECEIVABLE AND OTHER
Trade accounts receivable, net of allowance of nil	$ 37	$ 44
Imbalance receivable from affiliates		2
Other	6	2
Accounts receivable and other	43	48
Trade accounts receivable, allowance