Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2013 Investment	May 31, 2012	May 31, 2011	Nov. 30, 2011	Aug. 24, 2011	May 31, 2010
Summary Of Significant Accounting Policies [Line Items]
Advertising expenses	$ 982	$ 962	$ 1,013
Shipping and handling cost	3,951	4,184	3,638
Rental and lease equipment at net book value	234,856	243,173			15,896
Depreciation of equipment, straight line	428,957	414,631
Depreciation of equipment, accelerated	30,296	32,650
Tax impact realization likelihood percentage	50.00%
Uncertain tax positions settled				4,515		4,691
Interest and penalties	0	0		1,396
Demonstration equipment	6,057	5,495
Investment in money market funds	14	2,507
Number of investment funds	4
Trade accounts receivable terms	30-day terms
Assets, liabilities, revenues and expenses of foreign subsidiaries	Less than 10% of consolidated amounts
Rental equipment purchases	4,965	5,418
Sales of used equipment, not yet collected	11,419	10,021
Transfer of demonstration equipment, included in other assets, to rental and lease equipment	2,937	2,207
Agilent
Summary Of Significant Accounting Policies [Line Items]
Percentage of new equipment purchases	74.00%	75.00%	82.00%
Building
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	31 years 6 months
T&M equipment
Summary Of Significant Accounting Policies [Line Items]
Rental and lease equipment at net book value	230,074	239,620
DP equipment
Summary Of Significant Accounting Policies [Line Items]
Rental and lease equipment at net book value	4,782	3,553
Selling Expense
Summary Of Significant Accounting Policies [Line Items]
Reduction in operating expenses due to reclassification		10,710	10,010
General Expense
Summary Of Significant Accounting Policies [Line Items]
Reduction in operating expenses due to reclassification		10,710	10,010
Administrative Expenses
Summary Of Significant Accounting Policies [Line Items]
Reduction in operating expenses due to reclassification		$ 10,710	$ 10,010
Minimum
Summary Of Significant Accounting Policies [Line Items]
Operating lease agreements Period	1 year
Finance lease agreements Period	1 year
Minimum | Accelerated Depreciation
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	2 years
Minimum | Furniture and other equipment
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	3 years
Minimum | Leasehold improvements
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	3 years
Minimum | Equipment
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	2 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Operating lease agreements Period	3 years
Finance lease agreements Period	3 years
Period for demonstration equipment included in other assets	2 years
Maximum | Accelerated Depreciation
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	4 years
Maximum | Furniture and other equipment
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	10 years
Maximum | Leasehold improvements
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	5 years
Maximum | Equipment
Summary Of Significant Accounting Policies [Line Items]
Property plant and equipment, useful life	10 years