Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
OPERATING ACTIVITIES:
Net loss	$ (7,760)	$ (10,635)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	17,579	17,282
Noncash interest expense	2,203	1,869
Inventory fair value adjustment	2,243
Loss on extinguishment of debt		6,686
Provision for doubtful accounts	85	132
Share-based compensation expense	448	514
Acquisition related-item	(1,320)
Deferred income taxes	(5,935)	(7,992)
Changes in operating assets and liabilities:
Accounts receivable, trade	1,877	6,367
Income taxes	(34)	(86)
Inventories	(5,023)	(3,524)
Other assets	(1,583)	359
Accounts payable	5,414	926
Deferred revenue	241	198
Accrued expenses and other liabilities	(12,707)	(22,340)
Cash used in operating activities	(4,272)	(10,244)
INVESTING ACTIVITIES:
Purchases of property and equipment	(963)	(2,167)
Receipt related to acquisition of business	1,116
Cash provided by (used in) investing activities	153	(2,167)
FINANCING ACTIVITIES:
Proceeds from long-term debt		142,147
Payment of debt issuance costs		(2,528)
Repayments of long-term debt	(1,673)	(143,684)
Proceeds from Revolving Credit Facility		24,000
Repayments of Revolving Credit Facility		(8,000)
Cash (used in) provided by financing activities	(1,673)	11,935
EFFECT OF EXCHANGES IN RATES ON CASH AND CASH EQUIVALENTS	406	41
NET CHANGE IN CASH AND CASH EQUIVALENTS	(5,386)	(435)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	29,388	18,578
CASH AND CASH EQUIVALENTS AT END OF PERIOD	24,002	18,143
SUPPLEMENTAL INFORMATION:
Income taxes paid, net of refunds	1,215	1,511
Interest paid	31,116	40,381
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Movement from inventory to property and equipment of instruments placed on rental agreements	2,775	2,025
August 2012 [Member]
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Exchange of debt instruments due to debt amendment August 2012		$ 468,241