Employee benefit plans and stock-based compensation plans (reflecting the two-for-one stock split (Tables)

12 Months Ended

Dec. 31, 2010

Employee benefit plans and stock-based compensation plans (Tables) [Abstract]

Weighted average assumptions to value options and SSRs Granted

	2010	2009	2008
Expected life of option	3-5 years	3-5 years	3-5 years
Risk-free interest rate	0.5%-2.4%	1.3%-2.4%	1.6%-3.4%
Expected volatility of stock	36%-41%	35%-39%	30%-37%
Expected dividend yield	None	None	None
Weighted average volatility of stock	38.4%	37.5%	30.0%

Status of stock options and SSRs

	2010
(share data in millions)	Shares			Weighted- Average Exercise Price
Outstanding at beginning of year		16.4		$	20.77
Granted		2.5			49.55
Exercised		(5.1	)		15.44
Forfeited/cancelled		(0.5	)		29.92
Outstanding at end of period		13.3			27.83
Awards exercisable at period end		7.1			21.75

Status of restricted stock and performance shares

	2010
(share data in millions)	Shares			Weighted- Average Grant Date Fair Value
Outstanding at beginning of year		1.2		$	23.66
Granted		0.3			49.59
Other(1)		0.2			49.34
Released		(0.7	)	$	15.10
Forfeited/Cancelled		—
Outstanding at end of period		1.0

Total stock options exercised and restricted shares vested

(in millions, except per share data)	2010		2009		2008
Proceeds from stock options exercised	$	38.2	$	9.4	$	27.7
Fair value of vested restricted shares		10.5		12.4		4.3
Intrinsic value of stock options exercised		123.7		48.8		41.7
Weighted average fair value of options granted during the year	$	15.97	$	7.27	$	8.94