Stock-Based Compensation - Exercise Price for Stock Options Outstanding and Exercisable (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Exercise prices for stock options outstanding and exercisable
Number of stock options outstanding (in shares)	7,965,501
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 40.10
Stock options
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 80.00
Number of stock options outstanding (in shares)	13,715,612	14,202,039	8,847,734	7,923,009
Options Outstanding, Weighted-Average Remaining Contractual Life	6 years 10 months 28 days	6 years 6 months 14 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 41.71	$ 42.08	$ 43.90	$ 36.21
Number of stock options exercisable	2,507,834	1,781,153	1,772,608
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 44.93	$ 41.41	$ 35.13
Stock options | Range Of Exercise Prices $10.01 - $20.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	10.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 20.00
Number of stock options outstanding (in shares)	616,160
Options Outstanding, Weighted-Average Remaining Contractual Life	6 months	6 months
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 15.39
Number of stock options exercisable	16,160
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 15.62
Stock options | Range of Exercise Prices $20.01 - $30.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	20.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 30.00
Number of stock options outstanding (in shares)	844,483
Options Outstanding, Weighted-Average Remaining Contractual Life	3 years 5 months 19 days	3 years 3 months 3 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 26.70
Number of stock options exercisable	125,773
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 24.00
Stock options | Range of Exercise Prices $30.01 - $40.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	30.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 40.00
Number of stock options outstanding (in shares)	7,193,563
Options Outstanding, Weighted-Average Remaining Contractual Life	7 years 11 months 15 days	7 years 6 months 3 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 35.64
Number of stock options exercisable	1,138,849
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 35.52
Stock options | Range of Exercise Prices $40.01 - $50.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	40.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 50.00
Number of stock options outstanding (in shares)	1,567,428
Options Outstanding, Weighted-Average Remaining Contractual Life	7 years 6 months 29 days	7 years 1 month 2 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 47.50
Number of stock options exercisable	418,000
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 47.21
Stock options | Range of Exercise Prices $50.01 - $60.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	50.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 60.00
Number of stock options outstanding (in shares)	2,262,378
Options Outstanding, Weighted-Average Remaining Contractual Life	6 years 5 months 15 days	5 years 7 months 28 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 57.52
Number of stock options exercisable	440,952
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 56.93
Stock options | Range of Exercise Prices $60.01 - $70.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	60.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 70.00
Number of stock options outstanding (in shares)	1,216,600
Options Outstanding, Weighted-Average Remaining Contractual Life	6 years 4 months 9 days	5 years 7 months 13 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 64.19
Number of stock options exercisable	353,100
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 65.20
Stock options | Range of Exercise Prices $70.01 - $80.00
Exercise prices for stock options outstanding and exercisable
Exercise prices, outstanding stock option awards, low end of range (in dollars per share)	70.01
Exercise prices, outstanding stock option awards, high end of range (in dollars per share)	$ 80.00
Number of stock options outstanding (in shares)	15,000
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 72.89
Number of stock options exercisable	15,000
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 72.89