Common Stock and Stockholders' Equity - Fair Value Assumptions (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other disclosures
Compensation expense	$ 18,315	$ 13,523
Stock options
Fair value assumptions
Volatility, minimum (as a percent)	46.10%	47.50%
Volatility, maximum (as a percent)	47.90%	47.60%
Expected life (in years)	4 years 3 months 18 days	5 years 4 months 24 days
Risk-free interest rate, minimum	0.87%	2.50%
Risk-free interest rate, maximum	1.64%	2.55%
Dividend yield (as a percent)	0.00%	0.00%
Weighted-average fair value of the underlying stock options	$ 42.06	$ 27.87
Other disclosures
Compensation expense	$ 3,900	$ 5,500
Unrecognized compensation cost	$ 20,000
Period over which unrecognized compensation cost is expected to be recognized	1 year 9 months 18 days