Summary Of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2011

Summary Of Significant Accounting Policies [Abstract]

Earnings Per Common Share

	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
(Millions of Dollars, except per share amounts/Shares in Millions)	2011		2010		2011		2010
Net income for common stock	$	383	$	350	$	860	$	759
Weighted average common shares outstanding – Basic		292.9		283.0		292.5		282.2
Add: Incremental shares attributable to effect of potentially dilutive securities		1.7		1.6		1.7		1.5
Adjusted weighted average common shares outstanding – Diluted		294.6		284.6		294.2		283.7
Net income for common stock per common share – basic	$	1.31	$	1.24	$	2.94	$	2.69
Net income for common stock per common share – diluted	$	1.30	$	1.23	$	2.92	$	2.68