Debt (Narrative) (Details) (USD $) In Millions, unless otherwise specified					1 Months Ended				1 Months Ended	3 Months Ended	12 Months Ended		0 Months Ended	1 Months Ended		12 Months Ended					12 Months Ended			12 Months Ended
	Dec. 31, 2011	Mar. 31, 2011 Senior Secured Revolving Facility And/Or Term Loan Facility [Member]	Dec. 31, 2011 Term Loan Facility [Member]	Aug. 20, 2010 Term Loan Facility [Member] years	Aug. 20, 2010 Senior Secured Revolving Facility [Member] years	Dec. 31, 2011 Senior Secured Revolving Facility [Member]	Mar. 31, 2011 Letter Of Credit [Member]	Mar. 31, 2011 Swingline Loans [Member]	Mar. 31, 2011 Amended And Restated Credit Agreement [Member]	Mar. 31, 2011 Amended And Restated Credit Agreement [Member]	Dec. 31, 2011 Amended And Restated Credit Agreement [Member]	Dec. 31, 2011 Amended And Restated Credit Agreement [Member] Revolving Credit Facility Foreign Currency [Member]	Nov. 07, 2008 Senior Convertible Debentures [Member]	Jul. 31, 2009 Senior Convertible Debentures [Member]	Jul. 31, 2004 Senior Convertible Debentures [Member]	May 31, 2009 Senior Convertible Debentures [Member]	Dec. 31, 2008 Senior Convertible Debentures [Member]	Dec. 31, 2011 Federal Funds Rate [Member] Senior Secured Revolving Facility [Member]	Dec. 31, 2011 LIBOR [Member]	Dec. 31, 2011 LIBOR [Member] Senior Secured Revolving Facility [Member]	Dec. 31, 2011 Maximum [Member] Senior Secured Revolving Facility [Member]	Dec. 31, 2011 Minimum [Member] Term Loan Facility [Member]	Dec. 31, 2011 Minimum [Member] Senior Secured Revolving Facility [Member]	Dec. 31, 2011 Pre-Amendment [Member] Amended And Restated Credit Agreement [Member]	Dec. 31, 2011 Post-Amendment [Member] Amended And Restated Credit Agreement [Member]
Schedule Of Short And Long Term Debt [Line Items]
Credit facility, maximum borrowing capacity, foreign currencies												$ 100
Credit facility, maximum borrowing capacity				470	250
Senior secured credit facilities term, years				5	5
Amounts initially borrowed under senior secured facilities				470	100
Debt issuance costs					22				1
Amended credit agreement write off of deferred debt issuance cost											2
Repayments of long-term debt										49
Proceeds borrowed from other banks										49
Credit facility, amount available						248
Portion of facility available for issuance of letters of credit							50
Portion of facility available for issuance of swingline loans								10
Aggregate amount of additional credit facilities authorized		250
Basis spread on variable rate																		0.50%	1.75%	1.00%
Foreign subsidiary capital stock, maximum	65.00%
Percentage of net cash proceeds received from incurrence of indebtedness that must be used to prepay credit facility			100.00%
Percentage of net cash proceeds received from sale of assets outside normal course of business that must be used to prepay credit facility			100.00%
Minimum amount of assets sold outside normal course of business that require net cash proceeds to be used to prepay credit facility			5
Percentage of excess cash flow that must be used to prepay credit facility			50.00%
Credit agreement prepay requirement exception, leverage ratio																						2.5
Change in leverage ratio related to restricted payments																								1.75	2.00
Leverage ratio																					3.0
Interest coverage ratio																							4.5
Decrease in applicable interest margin											75.00%
Credit facility interest rate	2.05%
Borrowing outstanding											367
Letters of credit outstanding											2
Unamortized deferred debt issuance costs	15
Debentures in private placement															83
Debentures repurchased, Principal amount percentage													100.00%
Debentures, principal amount														20			55
Debentures conversion, shares														2			5
Purchase of convertible securities for cash																$ 8