Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	12 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2011
Cash Flows From Operating Activities:
Net Income	$ 60,456,206	$ 40,735,796	$ 34,962,641
Adjustments To Reconcile Net Income To Net Cash Provided By Operating Activities:
Depreciation	19,364,557	18,854,644	18,929,017
Amortization	9,998,590	3,740,043	3,237,065
Non-cash compensation expense	3,175,050	2,927,917	3,146,002
Non-cash interest expense	286,934	320,209	332,424
Provision for doubtful accounts	446,158	360,607	228,959
Deferred income tax expense (benefit)	3,365,810	2,504,754	(3,383,086)
Net (gain) loss on insurance settlement or sale of property, plant and equipment	(8,302,770)	166,183	(75,054)
Effects of changes in operating assets and liabilities, net of business acquisitions:
Accounts Receivable	(11,599,297)	(11,211,943)	(1,268,799)
Inventories	(4,453,680)	307,481	(11,291,056)
Prepaid expenses and other assets	(2,244,366)	(1,463,003)	303,161
Net change in billings related to costs and estimated earnings on uncompleted contracts	1,941,978	2,702,342	(6,192,210)
Accounts payable	957,646	2,420,530	2,653,172
Other accrued liabilities and income taxes	19,344,797	1,699,268	503,119
Net cash provided by operating activities	92,737,613	64,064,828	42,085,355
Cash flows from investing activities:
Proceeds from the sale or insurance settlement of property, plant and equipment	11,838,811	300,859	235,303
Acquisition of subsidiaries, net of cash acquired	(137,057,680)	(27,362,834)	(104,091,416)
Purchases of property, plant and equipment	(24,922,987)	(19,783,755)	(16,410,874)
Net cash used in investing activities	(150,141,856)	(46,845,730)	(120,266,987)
Cash flows from financing activities:
Proceeds from long-term debt	0	0	125,000,000
Debt acquisition costs	(100,000)	0	(1,254,002)
Tax benefits from stock options exercised	1,283,240	199,427	895,838
Proceeds from exercise of stock options and stock appreciation rights	15,781	48	379,955
Proceeds on revolving loan	0	0	12,000,000
Payments on revolving loan	0	0	(12,000,000)
Payments on long-term debt	(18,135,866)	0	(7,300,000)
Proceeds from settlement of derivative	0	0	834,416
Cash dividends paid	(13,423,199)	(12,565,821)	(12,466,812)
Net cash provided by (used in) financing activities	(30,360,044)	(12,366,346)	106,089,395
Effect of exchange rate changes on cash	59,372	60,077	(124,955)
Net increase (decrease) in cash and cash equivalents	(87,704,915)	4,912,829	27,782,808
Cash and cash equivalents at beginning of year	143,302,666	138,389,837	110,607,029
Cash and cash equivalents at end of year	55,597,751	143,302,666	138,389,837
Cash paid during the year for:
Interest	13,107,744	13,569,583	6,645,354
Income taxes	$ 30,967,378	$ 21,627,112	$ 13,849,749