Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income	Noncontrolling Interest [Member]
Balance, beginning of year, shares at Dec. 31, 2017		1,886
Balance, beginning of year at Dec. 31, 2017	$ 177,921	$ 0	$ 161,891	$ 15,945	$ 85
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	4,176		4,176
Dividends paid	(755)		(755)
Shares of common stock repurchased and retired (in shares)		0
Shares of common stock repurchased and retired	(29)		(29)
Stock options and stock appreciation rights exercised (in shares)		1
Stock options and stock appreciation rights exercised	(1)		(1)
Share-based compensation expense related to stock appreciation rights	62		62
Cumulative effect adjustment for adoption of new accounting standards	0		13,627	(13,627)
Net unrealized gain (loss) on investments	(1,309)			(1,309)
Net loss attributable to noncontrolling interests	(3)				(3)
Balance, end of year, shares at Mar. 31, 2018		1,887
Balance, end of year at Mar. 31, 2018	180,062	$ 0	178,971	1,009	82
Balance, beginning of year, shares at Dec. 31, 2018		1,887
Balance, beginning of year at Dec. 31, 2018	175,639	$ 0	174,690	949	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to the Company	6,626		6,626
Dividends paid	(755)		(755)
Shares of common stock repurchased and retired (in shares)		0
Shares of common stock repurchased and retired	(11)		(11)
Stock options and stock appreciation rights exercised (in shares)		2
Stock options and stock appreciation rights exercised	(1)		(1)
Share-based compensation expense related to stock appreciation rights	88		88
Net unrealized gain (loss) on investments	1,143			1,143
Net loss attributable to noncontrolling interests	0
Balance, end of year, shares at Mar. 31, 2019		1,889
Balance, end of year at Mar. 31, 2019	$ 182,729	$ 0	$ 180,637	$ 2,092	$ 0