Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2013
Cash flows from operating activities:
Net income	$ 40,497	$ 30,149	$ 32,714
Adjustments to reconcile net income to net cash provided by operating activities:
Earnings from unconsolidated affiliates		(822)	(992)
Depreciation and amortization	22,787	21,468	19,664
Loss on asset impairment and disposals	617	78	193
Amortization of deferred loan costs	223	223	222
Loss on investment in Venezuela	1,177
Venezuela devaluation		3,962
Foreign currency loss	1,509	4,185	943
Deferred income taxes	(729)	(1,040)	5,089
Gain on contingent consideration revaluation		(2,138)
Non-cash compensation cost	4,838	4,239	3,931
(Increase) decrease:
Receivables	(43,192)	(6,812)	(10,964)
Inventory	(925)	822	(1,405)
Prepaid expenses and other current assets	(2,525)	(17)	443
Increase (decrease):
Accounts payable	10,789	(295)	3,210
Other accrued liabilities	9,377	(1,208)	7,779
Income taxes	(972)	4,029	(2,184)
Net cash provided by operating activities	43,471	52,861	58,643
Cash flows from investing activities:
Capital expenditures	(28,769)	(33,016)	(26,068)
Proceeds from sale of assets	133	357	758
Business acquisitions, net of cash acquired	(3,075)	(10,175)	(18,589)
Change related to Venezuelan operations	(620)
Distributions from joint venture		2,223	1,000
Decrease in other assets, net	550	2
Net cash used in investing activities	(31,781)	(40,609)	(42,899)
Cash flows from financing activities:
Net (payments) borrowings under revolving credit agreement	8,000		(13,600)
Deferred consideration payments	(1,000)	(1,000)
Contingent consideration payments	(1,000)
Payments related to withholding tax for share-based payment arrangements	(1,775)	(1,710)	(1,534)
Corporate tax effect from share-based payment arrangements	3,034	1,131	2,996
Issuance of common stock from share-based payment arrangements	3,804	5,270	8,275
Purchase of treasury stock	(21,138)	(13,334)
Net cash used in financing activities	(10,075)	(9,643)	(3,863)
Effect of exchange rate changes on cash	(3,060)	(2,154)	(157)
Net increase (decrease) in cash and cash equivalents	(1,445)	455	11,724
Cash and cash equivalents at beginning of year	34,656	34,201	22,477
Cash and cash equivalents at end of year	33,211	34,656	34,201
Cash paid during the year for:
Interest	2,028	2,728	2,615
Income taxes	$ 21,491	$ 12,111	$ 12,926