Statement of Shareholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares
Issuance of redeemable convertible preferred stock, price per share (in dollars per share) | $ / shares	$ 16.3836
Issuance of redeemable convertible preferred stock, issuance costs	$ 0
Redeemable Convertible Preferred Stock
Issuance of redeemable convertible preferred stock, issuance costs	$ 100