Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2018	13,968,852
Balance at Dec. 31, 2018	$ 14	$ 70,451	$ (24,010)	$ (69)	$ 46,386
Exercise of stock options (in shares)	15,032
Exercise of stock options		131			131
Issuance of common stock in settlement of restricted and performance stock units, net of shares withheld for employee taxes, and stock awards (in shares)	51,491
Issuance of common stock in settlement of restricted and performance stock units, net of shares withheld for employee taxes, and stock awards		(490)			(490)
Stock-based compensation expense		1,307			1,307
Net loss			(8,220)		(8,220)
Net change in unrealized gain on available-for-sale investments				6	6
Balance (in shares) at Mar. 31, 2019	14,035,375
Balance at Mar. 31, 2019	$ 14	71,399	(32,230)	(63)	$ 39,120
Balance (in shares) at Dec. 31, 2019	14,315,586				14,315,586
Balance at Dec. 31, 2019	$ 14	82,346	(36,358)	(60)	$ 45,942
Exercise of stock options (in shares)	22,291				22,291
Exercise of stock options		200			$ 200
Issuance of common stock in settlement of restricted and performance stock units, net of shares withheld for employee taxes, and stock awards (in shares)	240,269
Issuance of common stock in settlement of restricted and performance stock units, net of shares withheld for employee taxes, and stock awards	$ 1	(2,234)			(2,233)
Stock-based compensation expense		1,980			1,980
Net loss			(12,414)		(12,414)
Net change in unrealized gain on available-for-sale investments				61	$ 61
Balance (in shares) at Mar. 31, 2020	14,578,146				14,578,146
Balance at Mar. 31, 2020	$ 15	$ 82,292	$ (48,772)	$ 1	$ 33,536