Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	May. 31, 2015 USD ($) plaintiff	May. 31, 2014 USD ($)	May. 31, 2013 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Advertising expenses	$ 928	$ 982	$ 982
Shipping and handling cost	3,953	3,977	3,951
Depreciation of rental and lease equipment	56,445	57,034	$ 56,795
Depreciation of equipment, straight line	440,495	427,005
Depreciation of equipment, accelerated	32,292	32,034
Rental and lease equipment at net book value	$ 231,671	221,888
Tax impact realization likelihood percentage	50.00%
Demonstration equipment	$ 81	$ 6,659
Trade accounts receivable terms	30 days
Assets, liabilities, revenues and expenses of foreign subsidiaries	less than 10% of our respective consolidated amounts
Restatement of previously recognized revenue	$ 1,300
Agilent
Summary Of Significant Accounting Policies [Line Items]
Percentage of new equipment purchases	71.00%	66.00%	74.00%
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	$ 225,222	$ 217,288
DP equipment
Summary Of Significant Accounting Policies [Line Items]
Rental and lease equipment at net book value	$ 6,449	$ 4,601
Minimum
Summary Of Significant Accounting Policies [Line Items]
Operating lease agreements Period	1 year
Finance lease agreements Period	1 year
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
Property plant and equipment, useful life	4 years
Period for demonstration equipment included in other assets	2 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
Other Income
Summary Of Significant Accounting Policies [Line Items]
Proceeds from legal settlements	$ 1,400
Parent Company [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of plaintiffs | plaintiff	1
Sales revenue | DP equipment
Summary Of Significant Accounting Policies [Line Items]
DP Revenue as Percentage of Total Revenue	8.30%