GEOGRAPHIC AREAS - Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 16,433	$ 9,374	$ 9,324
U.S.
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	15,700	8,260	8,069
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	206	460	579
Other foreign countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 527	$ 654	$ 676