Retirement Plans (Schedule of Valuation of the Company's Pension Plan Assets by Pricing Categories) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair value of plan assets	$ 210	$ 200
Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	191	180
Prices With Other Observable Inputs (Level 2) [Member]
Fair value of plan assets	2	2
Prices With Unobservable Inputs (Level 3) [Member]
Fair value of plan assets	17	18
Cash and Cash Equivalents [Member]
Fair value of plan assets	5	4
Cash and Cash Equivalents [Member] | Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	5	4
US companies [Member]
Fair value of plan assets	71	58
US companies [Member] | Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	71	58
International Companies [Member]
Fair value of plan assets	10	21
International Companies [Member] | Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	10	21
Corporate Debt Securities [Member]
Fair value of plan assets	102	93
Corporate Debt Securities [Member] | Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	100	91
Corporate Debt Securities [Member] | Prices With Other Observable Inputs (Level 2) [Member]
Fair value of plan assets	2	2
Other Pension Plan [Member]
Fair value of plan assets	22	24
Other Pension Plan [Member] | Quoted Prices In Active Markets (Level 1) [Member]
Fair value of plan assets	5	6
Other Pension Plan [Member] | Prices With Unobservable Inputs (Level 3) [Member]
Fair value of plan assets	$ 17	$ 18