Consolidated Statement of Stockholders' Equity (Unaudited) (USD $)	Total	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock	Common Class A	Common Class B
Beginning balance at Dec. 31, 2012	$ 400,034,094	$ 176,416,585	$ 26,394,577	$ 209,670,214	$ (12,713,193)	$ 209,419	$ 56,492
Beginning balance, shares at Dec. 31, 2012						20,941,821	5,649,240
Issuance of common stock (stock compensation plans)	2,166,226	2,164,715				1,511
Issuance of common stock (stock compensation plans), shares						151,126
Net income	6,475,436			6,475,436
Cash dividends declared	(2,854)			(2,854)
Grant of stock options		20,112		(20,112)
Tax benefit on exercise of stock options	98,929	98,929
Other comprehensive loss	(4,050,217)		(4,050,217)
Ending balance at Mar. 31, 2013	$ 404,721,614	$ 178,700,341	$ 22,344,360	$ 216,122,684	$ (12,713,193)	$ 210,930	$ 56,492
Ending balance, shares at Mar. 31, 2013						21,092,947	5,649,240