Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss)	$ 10,684	$ 1,578	$ (1,736)	$ (918)	$ (1,397)	$ (9,343)	$ 10,526	$ (11,658)
Denominator:
Denominator for basic income (loss) per share - weighted-average shares (in shares)	4,048,635			2,871,042			3,985,112	2,698,532
Effect of dilutive securities:
Equity incentive plans (in shares)	1,373,710			0			1,325,045	0
Denominator for diluted income (loss) per share (in shares)	5,422,345			2,871,042			5,310,157	2,698,532
Income (loss) per share - Basic (in dollars per share)	$ 2.64			$ (0.32)			$ 2.64	$ (4.32)
Income (loss) per share - Diluted (in dollars per share)	$ 1.97			$ (0.32)			$ 1.98	$ (4.32)