Common Stock, Preferred Stock and Equity Plans - Outstanding and Vested Stock Options (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Options
Stock options outstanding at beginning of period (in shares)	8,551
Stock options granted (in shares)	1,521
Stock options exercised (in shares)	(3,327)
Stock options forfeited (in shares)	(467)
Stock options expired (in shares)	(6)
Stock options outstanding at end of period (in shares)	6,272	8,551
Stock options exercisable at end of period (in shares)	3,333
Weighted-average Exercise Price
Weighted-average exercise price outstanding at beginning of period (usd per share)	$ 111.46
Weighted average exercise price, granted (usd per share)	184.50
Weighted average exercise price, exercised (usd per share)	95.57
Weighted average exercise price, forfeited (usd per share)	146.59
Weighted average exercise price, expired (usd per share)	182.96
Weighted-average exercise price outstanding at end of period (usd per share)	134.92	$ 111.46
Weighted average exercise price exercisable at the end of the period (usd per share)	$ 114.15
Weighted-average Remaining Contractual Life
Weighted-average Remaining Contractual Life, outstanding (in years)	7 years 1 month 13 days
Weighted-average Remaining Contractual Life, exercisable (in years)	6 years 21 days
Aggregate Intrinsic Value
Aggregate intrinsic value, outstanding	$ 522,740
Aggregate intrinsic value, exercisable	346,943
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of stock options exercised	325,900	$ 258,200	$ 302,800
Total cash received from employees as a result of employee stock option exercises	$ 317,800	$ 263,400	$ 323,300
Weighted Average
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market share price (usd per share)	$ 218.26