Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013
OPERATING ACTIVITIES:
Net loss	$ (15,902)	$ (26,947)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	52,858	52,603
Noncash interest expense	6,510	5,397
Loss on disposition and retirement of fixed assets	68	1,607
Inventory fair value adjustment	2,779	0
Loss on extinguishment of debt		9,111
Asset impairment	180
(Recovery) provision for doubtful accounts	(1,740)	193
Share-based compensation expense	1,175	1,167
Acquisition-related items	(4,638)	0
Deferred income taxes	(15,073)	(17,871)
Changes in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable, trade	5,330	2,130
Income taxes	861	2,492
Inventories	(14,651)	(10,857)
Other assets	(324)	394
Accounts payable	3,025	191
Deferred revenue	269	(368)
Accrued expenses and other liabilities	(10,186)	(24,070)
Cash provided by (used in) operating activities	10,541	(4,828)
INVESTING ACTIVITIES:
Purchases of property and equipment	(5,339)	(6,915)
Receipt related to acquisition of business	1,116
Acquisition of businesses, net of cash acquired	(5,151)
Cash used in investing activities	(9,374)	(6,915)
FINANCING ACTIVITIES:
Proceeds from long-term debt		288,076
Payment of debt issuance costs		(9,867)
Repayments of long-term debt	(5,008)	(286,666)
Proceeds from Revolving Credit Facility		47,000
Repayments of Revolving Credit Facility		(26,000)
Cash (used in) provided by financing activities	(5,008)	12,543
EFFECT OF EXCHANGES IN RATES ON CASH AND CASH EQUIVALENTS	481	142
NET CHANGE IN CASH AND CASH EQUIVALENTS	(3,360)	942
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	29,388	18,578
CASH AND CASH EQUIVALENTS AT END OF PERIOD	26,028	19,520
SUPPLEMENTAL INFORMATION:
Income taxes paid, net of refunds	3,030	2,174
Interest paid	71,179	81,315
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Movement from inventory to property and equipment of instruments placed on rental agreements	7,788	8,943
Tax Benefit from tax deduction contributed by IVD Holdings, Inc.		726
August 2012 [Member]
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Exchange of Debt Instruments Due to Debt Amendment		468,241
February 2013 [Member]
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Exchange of Debt Instruments Due to Debt Amendment		$ 467,406