Capitalization Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	Dec. 05, 2018	Dec. 03, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 28, 2018
Class of Stock [Line Items]
Issuance of common stock, net of issuance costs			$ (10)	$ 411,385	$ 0
Common stock, shares authorized			70,000,000	36,000,000
Document Period End Date			Dec. 31, 2019
Common stock, par value (usd per share)			$ 0.001	$ 0.001
Common stock, shares issued			28,456,508	28,404,316
Common stock, shares outstanding			28,456,508	28,404,316
Preferred stock, shares authorized			1,000,000	1,000,000
Preferred stock, par value (usd per share)			$ 0.001	$ 0.001
Preferred stock, shares outstanding			0	0
Preferred stock, shares issued			0	0
Underwritten Public Offering [Member] | Common Stock [Member]
Class of Stock [Line Items]
Issuance of common stock, net of issuance costs	$ 53,738	$ 358,256
Common stock, par value (usd per share)						$ 0.001
Stock Issued During Period, Length of Option to Purchase Overalltement	30 days
Common stock issued, shares	1,012,500	6,750,000		7,762,000