Consolidated Statement of Shareholders' Equity (Unaudited) (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance, beginning balance at Feb. 28, 2010	$ 227,866,038	$ 25,218,320	$ 8,174,206	$ 196,394,134	$ (672,858)	$ (1,247,764)
Balance, beginning balance (shares) at Feb. 28, 2010		25,218,320
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	379,955		146,241			233,714
Stock compensation	3,146,002		3,111,430			34,572
Stock Issued for SARs	(1,006,602)		(1,316,946)			310,344
Employee Stock Purchase Plan	647,892		521,093			126,799
Federal income tax deducted on stock options	895,838		895,838
Cash dividend paid	(12,466,812)			(12,466,812)
Net income	34,962,641			34,962,641
Foreign currency translation	1,055,071				1,055,071
Interest rate swap, net of (2013: $29,205, 2012: $29,205, 2011: ($292,046)	537,850				537,850
Balance, ending balance at Feb. 28, 2011	256,017,873	25,218,320	11,531,862	218,889,963	920,063	(542,335)
Balance, ending balance (shares) at Feb. 28, 2011		25,218,320
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options	48		8,150			(8,102)
Stock compensation	2,927,917		2,893,345			34,572
Restricted Stock Units	(77,997)		(90,996)			12,999
Stock Issued for SARs	(775,680)		(981,519)			205,839
Employee Stock Purchase Plan	763,291		640,542			122,749
Federal income tax deducted on stock options	199,427		199,427
Cash dividend paid	(12,565,821)			(12,565,821)
Net income	40,735,796			40,735,796
Foreign currency translation	438,148				438,148
Interest rate swap, net of (2013: $29,205, 2012: $29,205, 2011: ($292,046)	(54,237)				(54,237)
Balance, ending balance at Feb. 29, 2012	287,608,765	25,218,320	14,200,811	247,059,938	1,303,974	(174,278)
Balance, beginning balance (shares) at Feb. 29, 2012		25,218,320
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (shares)		7,488
Exercise of stock options	15,781	7,488	8,293			0
Stock compensation (shares)		14,000
Stock compensation	3,175,050	14,000	3,161,050			0
Restricted Stock Units	(413,379)		(516,916)			103,537
Stock Issued for SARs, Shares		89,662
Stock Issued for SARs	(1,191,919)	89,662	(1,296,943)			15,362
Employee Stock Purchase Plan (shares)		47,497
Employee Stock Purchase Plan	917,253	47,497	814,377			55,379
Federal income tax deducted on stock options	1,283,240		1,283,240
Cash dividend paid	(13,423,199)			(13,423,199)
Net income	60,456,206			60,456,206
Foreign currency translation	(4,439,087)				(4,439,087)
Interest rate swap, net of (2013: $29,205, 2012: $29,205, 2011: ($292,046)	(54,237)				(54,237)
Balance, ending balance at Feb. 28, 2013	$ 333,934,474	$ 25,376,967	$ 17,653,912	$ 294,092,945	$ (3,189,350)	$ 0
Balance, ending balance (shares) at Feb. 28, 2013		25,376,967