Share-Based Compensation (Schedule Of The Effects Of Share Based Compensation Included In The Consolidated Comprehensive Statement Of Earnings) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation [Abstract]
Gross general and administrative expense	$ 68	$ 57
Share-based compensation expense capitalized pursuant to the full-cost method of accounting for oil and gas properties	15	13
Related income tax benefit	$ 14	$ 14