Earnings per Share (Details) $ / shares in Units, $ in Thousands			3 Months Ended
		Jun. 14, 2019	Mar. 31, 2020 USD ($) $ / shares shares	Mar. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2019 shares
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Reverse stock split, ratio of shares surrendered to shares received		15
Numerator:
Net income (loss) | $			$ (20,145)	$ (5,275)
Denominator:
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders—basic	[1]		13,305,805	12,979,900
Weighted average diluted shares outstanding (in shares)	[1]		13,305,805	12,979,900
Net income (loss) per share attributable to common stockholders—basic | $ / shares	[1]		$ (1.51)	$ (0.41)
Net income (loss) per share attributable to common stockholders—diluted | $ / shares	[1]		$ (1.51)	$ (0.41)
Class A
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common stock, outstanding (in shares)			9,727,283		7,799,093
Numerator:
Net income (loss) | $			$ (13,363)	$ (2,313)
Net income (loss) attributable to common stockholders | $			$ (13,363)	$ (2,313)
Denominator:
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders—basic			8,826,116	5,691,984
Weighted average diluted shares outstanding (in shares)			8,826,116	5,691,984
Net income (loss) per share attributable to common stockholders—basic | $ / shares			$ (1.51)	$ (0.41)
Net income (loss) per share attributable to common stockholders—diluted | $ / shares			$ (1.51)	$ (0.41)
Class B
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common stock, outstanding (in shares)			3,654,248		5,464,196
Numerator:
Net income (loss) | $			$ (6,782)	$ (2,962)
Net income (loss) attributable to common stockholders | $			$ (6,782)	$ (2,962)
Denominator:
Weighted-average shares used to compute net income (loss) per share attributable to common stockholders—basic			4,479,689	7,287,916
Weighted average diluted shares outstanding (in shares)			4,479,689	7,287,916
Net income (loss) per share attributable to common stockholders—basic | $ / shares			$ (1.51)	$ (0.41)
Net income (loss) per share attributable to common stockholders—diluted | $ / shares			$ (1.51)	$ (0.41)
Class C
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Common stock, outstanding (in shares)			0		0

[1] Reflects the 1-for-15 reverse stock split that became effective on June 14, 2019.