Acquisitions and Investments (Acquisition of Hess' Retail Operations and Related Assets) (Details) $ in Millions	Sep. 30, 2014 USD ($) bbl / d	Sep. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,565	$ 1,566
Hess Retail Operations and Related Assets [Member]
Business Acquisition [Line Items]
Allocation of space on Colonial Pipeline (in barrels per day) | bbl / d	40,000
Cash paid for acquisition	$ 2,820
Net working capital adjustment estimate	(3)
Goodwill	$ 629