Equity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock-Based Compensation
Stock-based compensation expense	$ 47.6	$ 44.2	$ 41.4
Stock Options
Stock option activity
Options outstanding at the beginning of the period (in shares)	31,136,475	27,787,920	26,844,452
Options granted (in shares)	7,560,450	6,490,200	6,220,000
Options exercised (in shares)	(5,703,254)	(2,718,745)	(4,790,252)
Options forfeited (in shares)	(727,280)	(422,900)	(486,280)
Options outstanding at the end of the period (in shares)	32,266,391	31,136,475	27,787,920	26,844,452
Vested and non-vested options expected to vest at the end of the period (in shares)	30,542,834
Exercisable at the end of the period (in shares)	13,540,821
Weighted Average Exercise Price
Weighted average exercise price, options outstanding at the beginning of the period (in dollars per share)	$ 37.62	$ 31.60	$ 25.90
Weighted average exercise price, options granted (in dollars per share)	57.72	57.85	47.70
Weighted average exercise price, options exercised (in dollars per share)	25.80	23.71	20.27
Weighted average exercise price, options forfeited (in dollars per share)	50.17	41.73	34.55
Weighted average exercise price, options outstanding at the end of the period (in dollars per share)	44.14	$ 37.62	$ 31.60	$ 25.90
Weighted average exercise price, vested and non-vested options expected to vest (in dollars per share)	43.66
Weighted average exercise price, exercisable (in dollars per share)	$ 32.91
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term of options outstanding	7 years 11 days	6 years 11 months 1 day	7 years 1 month 2 days	7 years 29 days
Weighted average remaining contractual term of options vested options and non-vested expected to vest	6 years 11 months 16 days
Weighted average remaining contractual term of options exercisable	5 years 4 months 13 days
Aggregate Intrinsic Value
Aggregate intrinsic value of options outstanding	$ 744.1
Aggregate intrinsic value of options, vested and non-vested options expected to vest	718.9
Aggregate intrinsic value of options exercisable	$ 464.4
Status of the Company's non-vested options and changes during the year
Non-vested options at the beginning of the period (in shares)	17,323,040
Options granted (in shares)	7,560,450	6,490,200	6,220,000
Non-vested options, options vested (in shares)	(5,430,640)
Non-vested options, options forfeited (in shares)	(727,280)
Non-vested options at the end of the period (in shares)	18,725,570	17,323,040
Weighted Average Fair Value at Grant Date
Weighted average fair value at the grant date, options outstanding at the beginning of the period (in dollars per share)	$ 8.24
Weighted average fair value at grant date, options granted (in dollars per share)	7.39	$ 8.47	$ 8.64
Weighted average fair value at grant date, options vested (in dollars per share)	7.93
Weighted average fair value at grant date, options forfeited (in dollars per share)	8.28
Weighted average fair value at the grant date, options outstanding at the end of the period (in dollars per share)	$ 7.99	$ 8.24
Total intrinsic value of stock options exercised	$ 197.2	$ 88.1	$ 136.8
Total fair value of stock options vested	43.1	$ 39.9	$ 37.2
Total compensation cost related to non-vested options not yet recognized	$ 112.8
Weighted average expected amortization period	3 years 3 months 18 days
2000 Employee Option Plan
Stock-Based Compensation
Number of additional stock options that can be granted (in shares)	0
Options exercisable period	10 years
2009 Employee Option Plan
Stock-Based Compensation
Common Stock reserved for issuance	58,000,000
Shares available for the granting of additional stock options	12,078,110
Options ratable vesting period	5 years
Options exercisable period	10 years
2004 Directors Option Plan
Stock-Based Compensation
Shares available for the granting of additional stock options	140,000
Options exercisable period	10 years
Number of additional stock options expected to be granted (in shares)	0
2012 Directors Restricted Stock Plan | Restricted Shares
Stock-Based Compensation
Shares available for the granting of additional stock options	137,069
Weighted Average Fair Value at Grant Date
Fair value of restricted shares vested and issued (in dollar per share)	$ 57.97	$ 47.98	$ 38.76
Total fair value of restricted share awards vested (in dollars)	$ 1.0	$ 0.9	$ 1.0
Total compensation cost related to non-vested options not yet recognized	$ 0.4
Restricted share activity
Restricted shares outstanding at the beginning of the period (in shares)	17,256	18,340	26,880
Restricted shares granted (in shares)	16,905	17,948	18,340
Shares vested and issued (in shares)	(17,256)	(19,032)	(26,880)
Restricted shares outstanding at the end of the period (in shares)	16,905	17,256	18,340	26,880
Fair Value at Grant Date
Fair value at the grant date, restricted shares outstanding at the beginning of the period (in dollars per share)	$ 57.97	$ 47.72	$ 38.76
Fair value of restricted shares granted (in dollars per share)	57.99	57.85	47.72
Fair value of restricted shares vested and issued (in dollar per share)	57.97	47.98	38.76
Fair value at the grant date, restricted shares outstanding at the end of the period (in dollars per share)	$ 57.99	$ 57.97	$ 47.72	$ 38.76
Weighted Average Remaining Amortization Term (in years)	4 months 17 days	4 months 21 days	4 months 21 days	4 months 21 days
Selling, General and Administrative Expenses
Stock-Based Compensation
Stock-based compensation expense	$ 47.6	$ 44.2	$ 41.4
Stock-based compensation, net of tax	$ 36.2	$ 32.9	$ 30.3