Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Cash flows from operating activities:
Net income	$ 7,053	$ 4,477
Adjustments to reconcile net income to net cash provided by operating activities:
Earnings from unconsolidated affiliates		(443)
Depreciation and amortization	5,529	5,383
Amortization of deferred loan costs	56	55
Foreign currency loss	181	390
Deferred income taxes	271	2,092
Loss (gain) on asset disposals	34	(111)
Non-cash share-based compensation cost	975	870
(Increase) decrease:
Receivables	4,477	4,966
Inventory	(777)	(334)
Prepaid expenses and other current assets	(649)	359
Increase (decrease):
Accounts payable	(299)	(5,673)
Other accrued liabilities	(10,408)	(11,685)
Income taxes	(1,575)	(300)
Net cash provided by operating activities	4,868	46
Cash flows from investing activities:
Capital expenditures	(5,468)	(6,223)
Business acquisitions, net of cash acquired	(2,151)	(9,781)
Proceeds from sale of assets		148
Decrease in other assets, net	272
Net cash used in investing activities	(7,347)	(15,856)
Cash flows from financing activities:
Net (payments) borrowings under revolving credit agreement	(2,010)	14,870
Corporate tax effect from share-based payment arrangements	915	(33)
Issuance of common stock from share-based payment arrangements	892	671
Net cash (used in) provided by financing activities	(203)	15,508
Effect of exchange rate changes on cash	(496)	(227)
Net decrease in cash and cash equivalents	(3,178)	(529)
Cash and cash equivalents at beginning of period	34,656	34,201
Cash and cash equivalents at end of period	$ 31,478	$ 33,672