Nature of the Business and Basis of Presentation - (Details) $ / shares in Units, $ in Thousands					12 Months Ended
	Dec. 02, 2019 USD ($) $ / shares shares	Nov. 19, 2019 $ / shares shares	May 13, 2019 USD ($) $ / shares shares	May 03, 2019	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	May 14, 2019 shares
Nature of the Business
Reverse stock split ratio				0.1245
Issuance of stock (in shares) | shares	611,578	4,077,192
Share price | $ / shares	$ 36.75	$ 36.75
Proceeds from issuance of preferred stock, net of issuance costs | $	$ 160,900					$ 122,223
Proceeds from issuance of shares, net | $					$ 238,384
Underwriting discounts and commissions | $	10,300
Offering expenses | $	$ 1,000
Common stock, shares outstanding | shares			15,560,569		27,499,260	1,374,812
Preferred stock, shares issued | shares					0	0
Preferred stock, shares outstanding | shares			0		0	0	0
Common stock, number of shares authorized | shares			100,000,000		100,000,000	158,745,671
Common stock, par value per share | $ / shares			$ 0.001		$ 0.001	$ 0.001
Preferred stock, number of shares authorized | shares			10,000,000		10,000,000	0
Preferred stock, par value per share | $ / shares			$ 0.001		$ 0.001	$ 0.001
IPO
Nature of the Business
Issuance of stock (in shares) | shares			5,750,000
Share price | $ / shares			$ 15.00
Proceeds from issuance of shares, net | $			$ 76,900
Underwriting discounts and commissions | $			6,000
Offering expenses | $			$ 3,400