Stock-Based Compensation (Details 4) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Y	Dec. 31, 2011 Y	Dec. 31, 2010 Y
Stock Options / Stock Appreciation Rights
Assumptions used in determining the fair value of the stock-based awards
Risk-free interest rate, minimum (as a percent)	0.60%	0.90%	1.30%
Risk-free interest rate, maximum (as a percent)	1.20%	2.40%	2.70%
Volatility, minimum (as a percent)	38.40%	36.00%	35.20%
Volatility, maximum (as a percent)	42.90%	42.80%	38.80%
Expected life, minimum (in years)	4.02		4
Expected life, maximum (in years)	5.50		5
Expected life (in months/years)		5
Number of Shares
Outstanding at beginning of year (in shares)	7,029	6,780	7,886
Options and SARs granted (in shares)	1,895	1,469	1,041
Options and SARs exercised (in shares)	(972)	(1,032)	(1,795)
Options and SARs canceled (in shares)	(284)	(188)	(352)
Outstanding at end of year (in shares)	7,668	7,029	6,780
Exercisable at end of year (in shares)	4,575	4,355	4,278
Weighted Average Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 18.01	$ 15.73	$ 14.57
Options and SARs granted (in dollars per share)	$ 24.92	$ 26.72	$ 22.13
Options and SARs exercised (in dollars per share)	$ 15.60	$ 14.47	$ 13.91
Options and SARs canceled (in dollars per share)	$ 23.63	$ 22.96	$ 18.05
Outstanding at end of year (in dollars per share)	$ 19.82	$ 18.01	$ 15.73
Exercisable at end of year (in dollars per share)	$ 16.55	$ 14.65	$ 13.37
Additional disclosure about options and SARs
Aggregate intrinsic value of options and SARs outstanding	$ 26,600,000
Aggregate intrinsic value of options and SARs exercisable	25,700,000
Closing price of stock (in dollars per share)	$ 21.38
Weighted average grant date fair value (in dollars per share)	$ 8.88	$ 9.35	$ 7.64
Total intrinsic value of awards exercised	10,086,000	13,612,000	18,875,000
Employee Stock Purchase Plan
Assumptions used in determining the fair value of the stock-based awards
Risk-free interest rate, minimum (as a percent)		0.10%
Risk-free interest rate, maximum (as a percent)		0.20%
Risk-free interest rate (as a percent)	0.10%		0.20%
Volatility, minimum (as a percent)	31.00%	28.60%	28.80%
Volatility, maximum (as a percent)	48.30%	48.30%	29.90%
Expected life (in months/years)	6	6	6
ESPP period (in months)	6	6	6
Options
Additional disclosure about options and SARs
Cash received from exercises	$ 5,173,000	$ 7,189,000	$ 14,020,000