ACCOUNTS RECEIVABLE AND OTHER (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
ACCOUNTS RECEIVABLE AND OTHER
Trade accounts receivable, net of allowance of nil	$ 34	$ 44
Imbalance receivable from affiliates		2
Other	1	1
Accounts receivable and other	35	47	[1]
Trade accounts receivable, allowance	$ 0	$ 0

[1] Recast to consolidate PNGTS for all periods presented (Refer to Notes 2 and 6).