Stock Incentive Plans (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock incentive plan
Minimum exercise price to fair market value on the date of grant (as a percent)	100.00%
Stock Option Activity Roll Forward, Number of Shares
Options exercised (in shares)	(1,464,294)	(1,679,359)	(765,693)
Minimum
Stock incentive plan
Stock incentive plan vesting period	1 year
Maximum
Stock incentive plan
Stock incentive plan vesting period	3 years
Employee nonstatutory stock options
Stock Option Activity Roll Forward, Number of Shares
Options outstanding at the beginning of the period (in shares)	4,024,484	4,937,420	4,468,341
Options exercised (in shares)	(1,464,294)	(1,679,359)	(765,693)
Options forfeited (in shares)	(95,139)	(51,573)	(45,369)
Options terminated (in shares)	(1,381)	(10,995)	(7,011)
Options granted (in shares)	421,385	828,991	1,287,152
Options outstanding at the end of the period (in shares)	2,885,055	4,024,484	4,937,420
Stock Option Activity Roll Forward, Average Exercise Price
Average exercise price at the beginning of the period (in dollars per share)	$ 32.33	$ 25.08	$ 18.48
Options exercised (in dollars per share)	$ 23.46	$ 19.14	$ 15.76
Options forfeited (in dollars per share)	$ 52.17	$ 37.67	$ 22.30
Options terminated (in dollars per share)	$ 42.26	$ 15.74	$ 8.03
Options granted (in dollars per share)	$ 76.70	$ 49.01	$ 42.18
Average exercise price at the end of the period (in dollars per share)	$ 42.60	$ 32.33	$ 25.08
Stock Option Activity, Additional Disclosures
Weighted-Average Grant Date Fair Value (in dollars per share)	$ 19.26	$ 16.67	$ 15.44
Stock Option Activity Roll Forward, Non-vested, Number of Shares
Non-vested stock options at the beginning of the period (in shares)	2,067,673
Granted (in shares)	421,385
Vested/exercised (in shares)	(1,101,080)
Forfeited (in shares)	(105,053)
Non-vested stock options outstanding at the end of the period (in shares)	1,282,925	2,067,673
Stock Option Activity Roll Forward, Non-vested, Weighted-Average Grant Date Fair Value
Weighted average grant date fair value of non vested stock options at the beginning of the period (in dollars per share)	$ 14.90
Granted (in dollars per share)	$ 19.26
Vested/Exercised (in dollars per share)	$ 12.83
Forfeited (in dollars per share)	$ 16.44
Weighted average grant date fair value of non vested Stock options at the end of the period (in dollars per share)		$ 14.90
Summary of intrinsic value
Intrinsic value for the options outstanding	$ 160.5
Intrinsic value for the options exercisable	105.9
Total intrinsic value of all options exercised	$ 83.2	$ 65.3	$ 21.9
Exercise Price Range One [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	0 years 4 months 5 days
Exercise Price Range Three [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	1 year 4 months 4 days
Exercise Price Range Four [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	2 years 7 months 11 days
Exercise Price Range Five [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	2 years 10 months 1 day
Exercise Price Range Seven [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	3 years 11 months 5 days
Exercise Price Range Eight [Member] [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	4 years 3 months 28 days
Exercise Price Range Nine [Member] | Employee nonstatutory stock options
Stock incentive plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	4 years 5 months 28 days