Stockholders' Equity - Options Outstanding Separated Into Range of Exercise Price (Details)	12 Months Ended
	Dec. 31, 2019 $ / shares shares
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	454,348,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 4 months 4 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 20.628
Exercise price range, number of exercisable options (in shares) | shares	452,264,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 4 months 1 day
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 20.645
Range One
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	1,970,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	14 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 1.576
Exercise price range, number of exercisable options (in shares) | shares	1,970,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	14 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 1.576
Range Two
Class of Stock [Line Items]
Exercise price range, upper range limit (in usd per share)	8.800
Exercise price range, lower range limit (in usd per share)	$ 6.230
Exercise price range, number of outstanding options (in shares) | shares	11,856,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	1 year 11 months 27 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 8.084
Exercise price range, number of exercisable options (in shares) | shares	11,856,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	1 year 11 months 27 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 8.084
Range Three
Class of Stock [Line Items]
Exercise price range, upper range limit (in usd per share)	16.870
Exercise price range, lower range limit (in usd per share)	$ 12.470
Exercise price range, number of outstanding options (in shares) | shares	130,925,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 16 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 14.112
Exercise price range, number of exercisable options (in shares) | shares	128,841,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 4 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 14.057
Range Four
Class of Stock [Line Items]
Exercise price range, upper range limit (in usd per share)	21.660
Exercise price range, lower range limit (in usd per share)	$ 19.510
Exercise price range, number of outstanding options (in shares) | shares	164,253,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 7 months 1 day
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 21.177
Exercise price range, number of exercisable options (in shares) | shares	164,253,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 7 months 1 day
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 21.177
Range Five
Class of Stock [Line Items]
Exercise price range, upper range limit (in usd per share)	24.230
Exercise price range, lower range limit (in usd per share)	$ 22.010
Exercise price range, number of outstanding options (in shares) | shares	70,848,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 3 months 7 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 22.434
Exercise price range, number of exercisable options (in shares) | shares	70,848,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 3 months 7 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 22.434
Range Six
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	56,879,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	5 years 1 month 23 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 29.880
Exercise price range, number of exercisable options (in shares) | shares	56,879,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	5 years 1 month 23 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 29.880
Range Seven
Class of Stock [Line Items]
Exercise price range, number of outstanding options (in shares) | shares	17,617,000
Exercise price range, outstanding options, weighted average remaining contractual term (in years)	4 years 21 days
Exercise price range, outstanding options, weighted average exercise price (in usd per share)	$ 39.860
Exercise price range, number of exercisable options (in shares) | shares	17,617,000
Exercise price range, exercisable options, weighted average remaining contractual term (in years)	4 years 21 days
Exercise price range, exercisable options, weighted average exercise price (in usd per share)	$ 39.860