Stock-Based Compensation - Summary Of Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2018 $ / shares shares
Number of Shares
Outstanding beginning balance (in shares) | shares	4,636,353
Granted (in shares) | shares	0
Exercised (in shares) | shares	(3,625)
Forfeited (in shares) | shares	(14,736)
Expired (in shares) | shares	0
Canceled (in shares) | shares	0
Outstanding ending balance (in shares) | shares	4,617,992
Exercisable ending balance (in shares) | shares	4,040,320
Weighted Average Exercise Price
Outstanding beginning balance (in dollars per share) | $ / shares	$ 5.20
Granted (in dollars per share) | $ / shares	0.00
Exercised (in dollars per share) | $ / shares	14.00
Forfeited (in dollars per share) | $ / shares	14.00
Expired (in dollars per share) | $ / shares	0.00
Canceled (in dollars per share) | $ / shares	0.00
Outstanding ending balance (in dollars per share) | $ / shares	5.17
Exercisable ending balance (in dollars per share) | $ / shares	$ 3.90