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Significant Accounting Policies (Narrative) (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Sep. 30, 2019 segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accounting Policies [Line Items]
Number of principal reporting segments | segment	2	3
Restricted cash	$ 0		$ 0	$ 0
Accumulated depreciation relating to rental equipment				131,905,000
Options
Accounting Policies [Line Items]
Award vesting period (years)			5 years
Minimum
Accounting Policies [Line Items]
Estimated useful lives			3 years
Maximum
Accounting Policies [Line Items]
Estimated useful lives			25 years
Option term (years)			10 years
Rental Equipment
Accounting Policies [Line Items]
Accumulated depreciation relating to rental equipment	$ 14,587,000		$ 14,587,000	11,145,000
Selling, General and Administrative expenses
Accounting Policies [Line Items]
Advertising expense			12,177,000	11,773,000	$ 9,566,000
Product development and engineering costs			$ 11,984,000	$ 10,429,000	$ 9,849,000

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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