Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2014
Operating activities:
Net loss	$ (43,767)	$ (60,725)	$ (182,257)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	69,487	71,271	71,287
Noncash interest expense	11,541	10,222	8,761
Loss on disposition and retirement of fixed assets	1,027	374	93
Inventory fair value adjustment			2,889
Asset impairment loss	3,318		160,150
Provision for doubtful accounts	572	970	(1,666)
Share-based compensation expense	5,326	2,087	1,512
Deferred income taxes	(21,936)	12,127	(21,059)
Change in fair value of contingent consideration			(4,638)
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable, trade	5,443	(5,614)	2,154
Income taxes	(160)	111	(179)
Inventories	(11,967)	(3,097)	(15,589)
Other assets	1,394	(340)	(1,301)
Accounts payable	8,333	(1,375)	1,700
Deferred revenue	130	64	413
Accrued expenses and other liabilities	(1,650)	(485)	3,331
Cash provided by operating activities	27,091	25,590	25,601
Investing activities:
Purchases of property and equipment	(9,922)	(11,393)	(9,193)
Proceeds from sale of property and equipment	352
Receipt from acquisition of business related to finalizing certain working capital adjustments			1,151
Other investments	(4,850)	(5,300)
Acquisitions of businesses, net of cash acquired	(13,936)	(6,396)	(17,151)
Cash used in investing activities	(28,356)	(23,089)	(25,193)
Financing activities:
Repayments of long-term debt	(6,698)	(6,653)	(6,674)
Dividend payment	(350)
Proceeds from revolving facilities	75,000	55,500
Repayments of revolving facilities	(75,000)	(55,500)
Cash used in financing activities	(7,048)	(6,653)	(6,674)
Effect of exchange rates on cash and cash equivalents	213	(1,106)	499
Decrease in cash and cash equivalents	(8,100)	(5,258)	(5,767)
Cash and cash equivalents at beginning of period	18,363	23,621	29,388
Cash and cash equivalents at end of period	10,263	18,363	23,621
Supplemental information:
Income taxes paid, net of refunds	4,519	4,571	5,423
Interest paid	78,830	79,218	79,762
Non-cash investing and financing activities:
Movement from inventory to property and equipment of instruments placed on rental agreements	6,689	8,670	10,383
Fair value of contingent consideration liabilities at the date of acquisition	20,000	6,469	11,300
Non-cash dividend	$ 6,000