Long-Term Incentive Plans (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended				12 Months Ended															12 Months Ended	1 Months Ended	12 Months Ended
	Mar. 31, 2010	Mar. 31, 2009	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2011 Omnibus Plan [Member]	Dec. 31, 2011 Restricted Share Activity [Member]	Dec. 31, 2010 Restricted Share Activity [Member]	Dec. 31, 2009 Restricted Share Activity [Member]	Dec. 31, 2011 Restricted Share Units [Member]	Dec. 31, 2011 Stock Options [Member] years	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2009 Stock Options [Member]	Dec. 31, 2011 Performance Based Awards [Member]	Dec. 31, 2010 Performance Based Awards [Member]	Dec. 31, 2011 Deferred Cash Awards [Member]	Dec. 31, 2010 Deferred Cash Awards [Member]	Dec. 31, 2009 Deferred Cash Awards [Member]	Dec. 31, 2011 Maximum [Member]	Dec. 31, 2011 Maximum [Member] Performance Based Awards [Member]	Dec. 31, 2011 Minimum [Member]	Feb. 28, 2009 Chief Executive Officer [Member]	Dec. 31, 2009 Chief Executive Officer [Member]	Dec. 31, 2011 Board Of Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of shares of common stock reserved and available for issuance							6,000,000
Shareholder approved increase in common stock reserved and available for issuance							10,000,000
Shares issued under omnibus plan in connection with stock options, count			1
Shares issued under omnibus plan in connection with other than stock options, count			2
ISO and NQSO granted price at fair value of common stock, percentage			100.00%
Options exercisable in years																				5		4
Options expire in years																				10		7
Options granted	1,100,000	1,900,000		1,100,000	1,900,000		0					0			31,000								1	1,291,990
Options expired or canceled			225,874	1,493,873	1,167,374		225,874								15,136
Granted								235,050	805,776	2,194,686	0
Canceled								58,466	913,070	567,615	0
Number of Options			6,425,073	6,650,947	7,044,820	6,312,194									244,180
Shares/units available for future grants								6,533,715							105,820						350,000
Fair value of restricted shares awarded			$ 2	$ 4
Fair value of restricted shares cancelled			1	33
Unearned compensation, net of estimated forfeitures			11
Unearned compensation, net of estimated forfeitures, expected to be recognized, years			2.2
Unearned compensation amortized over vesting period, years																				5		3			10
Compensation expense related to restricted shares, net of estimated forfeitures								9	6	9		4	2	6	2	5	9	7	5
Tax benefit related to restricted share awards								2	2	3
Tax charge related to restricted share awards								1	1	1
Stock option awards exercised			2,211,878	2,050,252	2,006,620								0	0
Deferred tax asset write off												3	2
Unrecognized compensation cost												$ 5
Expected to be recognized as expense over a weighted average period, years												1.6
Grants restriction period, years			four												five
Long-term incentive awards vesting period, years, minimum			three														three
Long-term incentive awards vesting period, years, maximum			five														five