Derivative Financial Instruments (Schedule Of Derivative Financial Instruments Included In The Consolidated Comprehensive Statements Of Earnings) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivatives, Fair Value [Line Items]
Net gain (losses) recognized in comprehensive statements of earnings	$ 430	$ (307)
Oil, Gas And NGL Commodity Derivatives [Member]
Derivatives, Fair Value [Line Items]
Net gain (losses) recognized in comprehensive statements of earnings	294	(320)
Midstream Commodity Derivatives [Member]
Derivatives, Fair Value [Line Items]
Net gain (losses) recognized in comprehensive statements of earnings	2	(1)
Interest Rate Derivatives [Member]
Derivatives, Fair Value [Line Items]
Net gain (losses) recognized in comprehensive statements of earnings	1
Foreign Currency Derivatives [Member]
Derivatives, Fair Value [Line Items]
Net gain (losses) recognized in comprehensive statements of earnings	$ 133	$ 14