Business Segment Information (Details 3) (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	May 31, 2011	May 31, 2010
Business Segment Information
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
U.S. Department of Defense, other U.S. government agencies and their contractors
Business Segment Information
Sales									888,489	893,066	607,348
Percentage of total sales	43.00%				49.50%				43.00%	49.50%	44.90%
Aviation Supply Chain
Business Segment Information
Sales									588,406	465,108	405,955
Aviation Supply Chain | U.S. Department of Defense, other U.S. government agencies and their contractors
Business Segment Information
Sales									15,098	16,516	10,372
Government and Defense Services
Business Segment Information
Sales									552,687	571,343	194,944
Government and Defense Services | U.S. Department of Defense, other U.S. government agencies and their contractors
Business Segment Information
Sales									517,531	524,129	162,575
Maintenance, Repair and Overhaul
Business Segment Information
Sales									422,169	393,671	301,348
Maintenance, Repair and Overhaul | U.S. Department of Defense, other U.S. government agencies and their contractors
Business Segment Information
Sales									29,482	31,538	34,179
Structures and Systems
Business Segment Information
Sales									501,736	374,990	449,904
Structures and Systems | U.S. Department of Defense, other U.S. government agencies and their contractors
Business Segment Information
Sales									$ 326,378	$ 320,883	$ 400,222