Consolidated Statement Of Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2013	$ 6,615	$ 1	$ 5,080	$ (144)	$ 1,665	$ 13
Beginning Balance, shares at Dec. 31, 2013		143,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends declared ($0.04 per share)	(6)				(6)
Exercise of long-term incentive plan stock options, shares		0
Exercise of long-term incentive plan stock options	4		2	2
Treasury stock purchases, shares		0
Treasury stock purchases	(31)			(31)
Sendero divestiture	(4)		0			(4)
Tax benefit related to stock-based compensation	2		2
Pioneer Southwest merger transaction costs	(1)		(1)
Compensation costs:
Compensation costs included in net income	22		22			0
Net income	123				123	0
Ending Balance at Mar. 31, 2014	$ 6,724	$ 1	$ 5,105	$ (173)	$ 1,782	$ 9
Ending Balance, shares at Mar. 31, 2014		143,000,000