Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Jun. 25, 2018	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018
Common stock shares authorized			120,000,000	120,000,000
Common stock, par value per share			$ 0.001	$ 0.001
Preferred stock, authorized			10,000,000	10,000,000
Preferred stock par value per share			$ 0.001	$ 0.001
Issuance of stock (in shares)	6,591,800
Price per share	$ 26.42
Gross proceeds	$ 174,155	$ 163,034
Net proceeds	$ 162,878
Common stock, outstanding			34,497,542	34,410,725
Underwriter option to purchase
Issuance of stock (in shares)	859,800