Stock-Based Compensation and Employee Benefit Plan - Stock-based Compensation (Additional Information) (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Arrangements with Employees and Nonemployees [Abstract]
Capitalized stock-based compensation costs		$ 0			$ 0
Share-based compensation expense	$ 51,218,000		$ 7,818,000	$ 115,100,000	15,773,000
Unrecognized compensation cost related to unvested stock options	56,800,000			$ 56,800,000
Expense expected to be recognized over a weighted-average period				2 years 7 months 13 days
Excess tax benefits				$ 0	$ 0
Restricted Stock
Share-based Arrangements with Employees and Nonemployees [Abstract]
Unrecognized stock-based compensation cost	108,200,000			$ 108,200,000
Expense expected to be recognized over remaining weighted-average period				1 year 1 month 10 days
Employee Stock Option
Share-based Arrangements with Employees and Nonemployees [Abstract]
Unrecognized stock-based compensation cost	$ 6,300,000			$ 6,300,000
Expense expected to be recognized over remaining weighted-average period				10 months 28 days