Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	12 Months Ended
	May 31, 2002	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation pre-tax unrecognized compensation cost		$ 110.9
Weighted average period for recognizing compensation cost, in years		1.3
Income tax benefits realized from exercise of stock options and vesting of stock units and deferred stock units		79.0	123.5	68.0
End of year stock price		$ 32.28
In the money options exercisable		4,700,000
1998 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan		48,300,000
Exercise price of incentive stock options percentage of fair market value, minimum		100.00%
Exercise price of incentive stock options percentage of fair market value, minimum in certain cases		110.00%
Stock option vesting period, in years		4 years
Term of options granted, maximum period in years		10
Term of incentive options granted, maximum period, in years		5
Voting stock minimum percentage before applying incentive stock granted term limits		10.00%
2001 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan		5,000,000
Stock option vesting period, in years		4 years
Term of options granted, maximum period in years		10
Term of incentive options granted, maximum period, in years		5
Voting stock minimum percentage before applying incentive stock granted term limits		10.00%
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan		7,500,000
Exercise price of incentive stock options percentage of fair market value, minimum		100.00%
Exercise price of incentive stock options percentage of fair market value, minimum in certain cases		110.00%
Stock option vesting period, in years		4 years
Term of options granted, maximum period in years		7
2009 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan		8,500,000
Exercise price of incentive stock options percentage of fair market value, minimum		100.00%
Exercise price of incentive stock options percentage of fair market value, minimum in certain cases		110.00%
Stock option vesting period, in years		4 years
Term of options granted, maximum period in years		7
Stock Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of stock options granted		$ 14.93	$ 16.49	$ 8.44
Total pre-tax intrinsic value of options exercised		22.6	67.5	11.2
Total fair value of vested options		14.8	14.6	18.2
Proceeds from stock options exercised		12.6	33.6	11.9
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of equity instruments other than options granted		$ 32.48	$ 39.95	$ 21.56
Each DSU receives this number of shares of common stock upon vesting		1
Holder elect to defer vested shares period, minimum in years		1
Holder elect to defer vested shares period, maximum in years		10
The amount typically vested by anniversary grant date, percentage		50.00%
Equal installment percentage for remaining DSUs to be vested in two years from grant date		12.50%
Number of years from date of grant DSUs are fully vested		2
Director's minimum period of service before vesting accelerates, in years		1
Director's vesting before acceleration after departure, percentage		100.00%
Total pre-tax intrinsic value end of year		0.5	3.0	0.4
Total fair value of vested and distributed		0.5	1.4	0.6
Unvested Deferred Stock Units		68,583
Aggregate instrinsic value		2.2
Weighted average contractual remaining life, in years		1.2
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of equity instruments other than options granted		$ 33.75	$ 26.56	$ 18.73
Total pre-tax intrinsic value end of year		68.0	72.0	55.9
Total fair value of vested and distributed		44.7	47.2	92.6
Number of equity instruments other than options unnvested		6,500,000
Aggregate instrinsic value		181.9
Weighted average contractual remaining life, in years		1.6
Each RSU receives this number of shares of common stock upon vesting		1
Restricted stock unit vesting provision, minimum in years		3
Restricted stock unit vesting provision, maximum in years		4
1999 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock approved for issuance under plan		3,100,000
Maximum amount of shares available for issuance	1,500,000
Aggregate amount of shares available, maximum	20,000,000
Discount on fair market value for purchase of stock, percentage		15.00%
Issuance of common stock under employee stock purchase plan, shares		500,000	500,000	700,000
Weighted average purchase price		$ 25.75	$ 25.62	$ 13.47
Total cash proceeds from shares purchased		12.7	12.2	9.8
Amount withheld from employees for future purchases		1.4
Weighted average fair value of equity instruments other than options granted		$ 10.24	$ 9.86	$ 4.11
Capitalized Internal Use Software [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional stock based compensation		$ 7.3	$ 7.5	$ 6.4