Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016 USD ($) Division Segment shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Aug. 31, 2015 shares	May 31, 2008 shares
Accounting Policies [Abstract]
Number of divisions | Division	4
Number of reportable segments | Segment	4
Impairments of long-lived assets	$ 0	$ 0	$ 0
Period for warranties for rental equipment	90 days
Period for warranties for equipment manufactured	1 year
Property, plant and equipment depreciation expenses	$ 8,100,000	8,200,000	7,600,000
Capitalized in internal use of software	200,000	600,000
Total advertising expenses	$ 2,900,000	2,800,000	2,400,000
Estimated useful life (In years), Customer relationships	11 years
Goodwill and trade name intangible assets	$ 33,500,000	33,500,000
Goodwill and intangible assets impairment charge	$ 0	0	$ 0
Common stock shares authorized for repurchase | shares				2,000,000	2,000,000
Shares remain authorized for repurchase | shares	1,592,026
Unbilled receivables related to end-of-lease services	$ 28,100,000	25,000,000
Period for credit risk identified	30 days
Estimated fair value notes payable	$ 140,700,000	160,600,000
Recorded fair value of notes payable	$ 140,000,000	$ 160,000,000