Employee Benefits (Fair Value Measurements Using Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified				12 Months Ended		12 Months Ended
	Dec. 31, 2011 U.S. Pension Plan [Member] Private Equity [Member]	Dec. 31, 2010 U.S. Pension Plan [Member] Private Equity [Member]	Dec. 31, 2009 U.S. Pension Plan [Member] Private Equity [Member]	Dec. 31, 2010 U.S. Pension Plan [Member] Alternative Investments [Member]	Dec. 31, 2011 U.S. Pension Plan [Member] Alternative Investments [Member]	Dec. 31, 2011 U.K. Pension Plan [Member] Alternative Investments [Member]	Dec. 31, 2010 U.K. Pension Plan [Member] Alternative Investments [Member]	Dec. 31, 2011 Non-US Pension Plan (Excluding U.K.) [Member] Insurance Group Annuity Contract [Member]	Dec. 31, 2010 Non-US Pension Plan (Excluding U.K.) [Member] Insurance Group Annuity Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, beginning balance, Assets	$ 2	$ 2	$ 2	$ 13	$ 19	$ 33	$ 24	$ 36	$ 31
Purchases and sales, net				4		(1)	7	24	1
Unrealized gains (losses)				2			2	(3)	4
Fair Value, ending balance, Assets	$ 2	$ 2	$ 2	$ 19	$ 19	$ 32	$ 33	$ 57	$ 36