Summary Of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2012

Summary Of Significant Accounting Policies [Abstract]

Earnings Per Common Share

(Millions of Dollars, except per share amounts/Shares in Millions)	2012		2011
Net income for common stock	$	277	$	311
Weighted average common shares outstanding – Basic		292.9		292.0
Add: Incremental shares attributable to effect of potentially dilutive securities		1.6		1.6
Adjusted weighted average common shares outstanding – Diluted		294.5		293.6
Net income for common stock per common share – basic	$	0.95	$	1.07
Net income for common stock per common share – diluted	$	0.94	$	1.06