Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2010	May 31, 2012 item	May 31, 2011	May 31, 2010
Business Segment Information
Number of business segments									4
Business Segment Information
Net sales	$ 563,346	$ 534,195	$ 481,922	$ 485,535	$ 487,826	$ 458,035	$ 447,054	$ 412,197	$ 2,064,998	$ 1,805,112	$ 1,352,151
Gross profit	77,335	86,958	78,556	75,708	83,199	78,793	74,176	70,888	318,557	307,056	243,519
Total assets	2,195,653				1,703,727				2,195,653	1,703,727	1,500,181
Capital expenditures									91,218	124,879	28,855
Depreciation and amortization									80,333	59,296	38,930
Aviation Supply Chain
Business Segment Information
Net sales									588,406	465,108	405,955
Gross profit									106,029	76,247	70,490
Total assets	628,434				533,315				628,434	533,315	546,067
Capital expenditures									4,894	2,714	3,965
Depreciation and amortization									15,580	12,126	13,472
Government and Defense Services
Business Segment Information
Net sales									552,687	571,343	194,944
Gross profit									78,635	105,538	42,304
Total assets	537,679				501,351				537,679	501,351	307,864
Capital expenditures									67,909	107,699	2,830
Depreciation and amortization									39,386	26,572	4,007
Maintenance, Repair and Overhaul
Business Segment Information
Net sales									422,169	393,671	301,348
Gross profit									55,488	55,871	38,206
Total assets	224,752				234,701				224,752	234,701	220,159
Capital expenditures									5,844	5,329	7,097
Depreciation and amortization									6,284	6,661	6,904
Structures and Systems
Business Segment Information
Net sales									501,736	374,990	449,904
Gross profit									78,405	69,400	92,519
Total assets	644,570				293,437				644,570	293,437	276,297
Capital expenditures									11,135	5,912	12,914
Depreciation and amortization									14,559	9,066	10,625
Corporate
Business Segment Information
Total assets	160,218				140,923				160,218	140,923	149,794
Capital expenditures									1,436	3,225	2,049
Depreciation and amortization									$ 4,524	$ 4,871	$ 3,922