Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2011

Share-Based Compensation [Abstract]

Summary of stock-based compensation costs

	2011			2010			2009
Stock-based compensation cost	$	108		$	87		$	88
Tax benefit		(22	)		(18	)		(15	)
Stock-based compensation cost, net of tax	$	86		$	69		$	73

Weighted average assumptions used in the option pricing model for options granted

	2011			2010			2009
Expected life (years)		5.0			5.0			6.0
Risk-free interest rate		1.8	%		2.2	%		2.6	%
Volatility		40.8	%		39.8	%		41.2	%
Dividend yield		0.9	%		1.2	%		1.8	%
Weighted average fair value per share at grant date	$	24.20		$	16.24		$	12.66

Summary of stock options outstanding and related information

	Number of Options	Weighted Average Exercise Price Per Option
Outstanding at December 31, 2010	10,902	$        50.72
Granted	1,281	68.94
Exercised	(2,636)	43.05
Forfeited	(78)	52.29
Expired	(37)	59.10
Outstanding at December 31, 2011	9,432	$        55.34

Summary of information about stock options outstanding

			Outstanding				Exercisable
Range of Exercise Prices			Number of Options		Weighted Average Remaining Contractual Life (In years)	Weighted Average Exercise Price Per Option	Number of Options		Weighted Average Remaining Contractual Life (In years)	Weighted Average Exercise Price Per Option
$ 14.79    -	$	16.78		3	1.8	$    15.84		3	1.8	$      15.84
22.88   -		33.32		1,536	6.1	28.76		1,274	5.9	28.69
34.45   -		50.94		2,841	7.1	43.73		1,578	6.3	42.10
51.73   -		77.41		3,930	6.6	67.14		2,704	5.3	66.01
77.84   -		86.50		1,122	4.6	79.91		1,122	4.6	79.91
Total				9,432	6.4	$    55.34		6,681	5.5	$      55.56

Summary of Restricted stock Awards

	RSA Number of Shares			Weighted Average Grant Date Fair Value Per Share	RSU Number of Units			Weighted Average Grant Date Fair Value Per Unit
Unvested balance at December 31, 2010		1,399		$    43.05		1,098		$    46.60
Granted		698		62.85		351		63.33
Vested		(691	)	46.24		(421	)	47.38
Forfeited		(94	)	49.72		(88	)	51.06
Unvested balance at December 31, 2011		1,312		$    51.43		940		$    52.08

Stock compensation relating to Black-Scholes option pricing model

	2011			2010			2009
Expected life (years)		1.0			1.0			1.0
Risk-free interest rate		0.1	%		0.2	%		0.3	%
Volatility		36.6	%		44.2	%		69.5	%
Dividend yield		1.0	%		1.5	%		1.9	%
Fair value per share of the 15% cash discount		$    9.62			$    6.16			$    4.81
Fair value per share of the look-back provision		6.50			4.98			8.44
Total weighted average fair value per share at grant date		$  16.12			$  11.14			$  13.25