Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011 segment	Nov. 30, 2010	Nov. 30, 2011 Aviation Supply Chain	Nov. 30, 2010 Aviation Supply Chain	Nov. 30, 2011 Aviation Supply Chain	Nov. 30, 2010 Aviation Supply Chain	Nov. 30, 2011 Government and Defense Services	Nov. 30, 2010 Government and Defense Services	Nov. 30, 2011 Government and Defense Services	Nov. 30, 2010 Government and Defense Services	Nov. 30, 2011 Maintenance, Repair and Overhaul	Nov. 30, 2010 Maintenance, Repair and Overhaul	Nov. 30, 2011 Maintenance, Repair and Overhaul	Nov. 30, 2010 Maintenance, Repair and Overhaul	Nov. 30, 2011 Structures and Systems	Nov. 30, 2010 Structures and Systems	Nov. 30, 2011 Structures and Systems	Nov. 30, 2010 Structures and Systems	Nov. 30, 2011 Structures and Systems Error correction related to inventory adjustments	Aug. 31, 2011 Structures and Systems Error correction related to inventory adjustments	May 31, 2011 Structures and Systems Error correction related to inventory adjustments
Business Segment Information
Number of business segments (in segments)			4
Business Segment Information
Sales	$ 475,902	$ 440,522	$ 955,192	$ 844,915	$ 143,351	$ 111,324	$ 298,225	$ 211,590	$ 142,389	$ 134,406	$ 292,388	$ 263,736	$ 91,881	$ 99,041	$ 185,058	$ 175,860	$ 98,281	$ 95,751	$ 179,521	$ 193,729
Gross profit	77,156	73,678	151,996	143,679	25,724	19,340	51,023	38,580	23,933	24,129	51,342	47,151	13,464	12,290	23,725	22,397	14,035	17,919	25,906	35,551
Out-of-period expenses related to inventory adjustment																					$ 2,157	$ 1,236	$ 921