Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]
Beginning balance at Dec. 31, 2017	$ 88,834	$ 73	$ 12,311	$ (1,430)	$ 77,880
Beginning balance, shares at Dec. 31, 2017		7,301
Common stock issued on exercise of options and vesting of restricted stock units and performance awards	53		53
Common stock issued on exercise of options and vesting of restricted stock units and performance awards, shares		7
Common stock repurchased on vesting of restricted stock units	(76)		(76)
Common stock repurchased on vesting of restricted stock units, shares		(1)
Share-based compensation expense	1,542		1,542
Cash dividends on common stock	(1,826)				(1,826)
Unrealized gain (loss) on investments, net of tax	(3,964)			(3,964)
Net loss	(9,123)				(9,123)
Ending balance at Mar. 31, 2018	75,440	$ 73	13,830	(5,394)	66,931
Ending balance, shares at Mar. 31, 2018		7,307
Beginning balance at Dec. 31, 2018	119,037	$ 74	15,437	(5,068)	108,594
Beginning balance, shares at Dec. 31, 2018		7,395
Common stock issued on exercise of options and vesting of restricted stock units and performance awards	122		122
Common stock issued on exercise of options and vesting of restricted stock units and performance awards, shares		17
Common stock repurchased on vesting of restricted stock units	(178)		(178)
Common stock repurchased on vesting of restricted stock units, shares		(2)
Share-based compensation expense	1,387		1,387
Cash dividends on common stock	(1,852)				(1,852)
Unrealized gain (loss) on investments, net of tax	3,657			3,657
Net loss	(2,300)				(2,300)
Ending balance at Mar. 31, 2019	$ 119,873	$ 74	$ 16,768	$ (1,411)	$ 104,442
Ending balance, shares at Mar. 31, 2019		7,410