Consolidated Condensed Statements Of Cash Flows (USD $) In Thousands	3 Months Ended
	Aug. 31, 2011	Aug. 31, 2010
Cash Flows From Operating Activities:
Net income	$ 6,794	$ 3,806
Adjustments to reconcile net income to net cash provided by operating activities:
Earnings from unconsolidated affiliates	(442)	(308)
Income attributable to non-controlling interest	19
Depreciation and amortization	4,139	3,122
Amortization of deferred loan costs	75	78
Foreign currency loss (gain)	271	(41)
Deferred income taxes	2,451	133
Non-cash compensation cost	1,165	1,146
(Increase) decrease:
Receivables	14,715	16,318
Inventory	(882)	121
Prepaid expenses and other current assets	301	(2)
Increase (decrease):
Accounts payable	(8,132)	(7,146)
Other accrued liabilities	(5,050)	765
Income taxes	345	49
Net cash provided by operating activities	15,769	18,041
Cash Flows From Investing Activities:
Capital expenditures	(5,270)	(2,295)
Proceeds from sale of assets	163
Increase in other assets, net	(643)
Net cash used in investing activities	(5,750)	(2,295)
Cash Flows From Financing Activities:
Payments under revolving credit agreement, net	(3,052)	(10,000)
Payments related to term and auto notes	(90)	(77)
Tax effect from share- based payment arrangements	233	3
Issuance of common stock from share- based payment arrangements	131	5
Purchase of treasury stock		(1,344)
Net cash used in financing activities	(2,778)	(11,413)
Effect Of Exchange Rate Changes On Cash	5	144
Net Increase In Cash And Cash Equivalents	7,246	4,477
Cash And Cash Equivalents At Beginning Of Period	14,078	12,610
Cash And Cash Equivalents At End Of Period	$ 21,324	$ 17,087