Condensed Consolidated Statements Of Income (Loss) And Retained Earnings (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
NET SALES	$ 43,331,983	$ 35,525,254	$ 66,793,534	$ 56,889,719
COST OF SALES	32,273,760	28,247,109	55,812,274	50,023,334
Gross profit from operations	11,058,223	7,278,145	10,981,260	6,866,385
SELLING, GENERAL AND ADMINISTRATIVE EXPENSES	3,858,260	3,484,672	7,504,455	7,235,077
Income (loss) from operations	7,199,963	3,793,473	3,476,805	(368,692)
OTHER INCOME (EXPENSE):
Interest income	39,491	26,671	61,659	59,720
Interest expense	(71,475)	(91,049)	(125,929)	(138,695)
Gain on sale of equity investments	0	812,588	0	3,881,872
Dividend income	95,846	737,264	199,846	1,486,000
Other, net	277,786	(30,675)	263,585	(33,126)
Total other income (expense)	341,648	1,454,799	399,161	5,255,771
Income from continuing operations before income taxes	7,541,611	5,248,272	3,875,966	4,887,079
PROVISION FOR INCOME TAXES	2,110,000	1,362,000	1,085,000	1,261,000
Equity in affiliate income (loss), net of tax	57,064	(10,031)	5,838	(12,253)
Net income from continuing operations	5,488,675	3,876,241	2,796,804	3,613,826
Discontinued operations:
Loss from operations of Tulsa Dynaspan, Inc. and Beaver Lake Concrete, Inc. (including gain on disposal of assets of $0, $0, $0, and $0, respectively)	0	(2,648,143)	(177,306)	(4,976,169)
BENEFIT FROM INCOME TAXES	0	(635,000)	(50,000)	(1,284,000)
Net loss from discontinued operations	0	(2,013,143)	(127,306)	(3,692,169)
NET INCOME (LOSS)	5,488,675	1,863,098	2,669,498	(78,343)
RETAINED EARNINGS, beginning of period	95,699,369	95,816,572	98,518,546	97,758,013
Dividends, Common Stock, Cash	911,290	923,136	911,290	923,136
Stock Repurchased and Retired During Period, Value	28,813	342,872	28,813	342,872
RETAINED EARNINGS, end of period	$ 100,247,941	$ 96,413,662	$ 100,247,941	$ 96,413,662
Basic earnings (loss) per share:
From continuing operations	$ 1.39	$ 0.96	$ 0.71	$ 0.90
From discontinued operations	$ 0.00	$ (0.50)	$ (0.03)	$ (0.92)
Net earnings (loss) per share	$ 1.39	$ 0.46	$ 0.68	$ (0.02)
Common Stock, Dividends, Per Share, Declared	$ 0.23	$ 0.23	$ 0.23	$ 0.23