Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 24, 2011	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Maximum shares of common stock to be awarded		36,700,000		36,700,000
Remaining shares available		14,700,000		14,700,000
Unrecognized compensation expense		$ 84.0		$ 84.0
Approved grants of incentive equity awards	46
Incentive equity awards vesting ratably over a period, in years				2.9
Stock-based compensation expense		12	10	21	20
Recognized net tax benefit		5	4	8	8
Excess tax benefits available to absorb tax deficiencies				17	13
Employee service share-based compensation, APIC pool balance				29
Weighted average remaining contractual life, years		0.7		0.7
Vesting term, in years	four
Aggregate intrinsic value		1.2		1.2
Payment of taxes for net share settlement				29	22
SSARs [Member]
Number of units, vested/exercised				0
Restricted Stock Units (RSUs) [Member]
Excess tax benefits available to absorb tax deficiencies				17
Number of units, vested/exercised				2,800,000
Stock Option [Member]
Converted stock options outstanding		2,000,000		2,000,000
Weighted average exercise price		$ 38.70		$ 38.70
Options exercisable		2,000,000		2,000,000
Stock options outstanding		200,000		200,000
Performance Stock [Member]
Unrecognized compensation expense		9.5		9.5
Amount authorized for grant to employees and senior officers	$ 11
Converted stock options outstanding		350,000		350,000