Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Operating Activities
Net income		$ 80,245	$ 57,804	[1]	$ 63,103	[2]
Adjustments to reconcile net income to cash provided by operating activities:
Provision for doubtful accounts		506	860	[2]	575	[2]
Depreciation - PP&E		21,229	19,264	[2]	14,934	[2]
Depreciation - Rental		8,613	9,830	[2]	9,373	[2]
Amortization of intangibles		14,637	14,746	[2]	5,658	[2]
Amortization of debt issuance		667	634	[2]	295	[2]
Stock-based compensation expense		5,987	4,119	[2]	3,269	[2]
Provision for deferred income tax (benefit) expense		(1,182)	(855)	[2]	3,383	[2]
Gain on sale of property, plant and equipment		(3,779)	(1,094)	[2]	(912)	[2]
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable		(27,571)	28,064	[2]	11,447	[2]
Inventories		(78,463)	38,275	[2]	393	[2]
Rental equipment		1,138	4,542	[2]	(20,729)	[2]
Prepaid expenses and other		(6,994)	6,373	[2]	(4,633)	[2]
Trade accounts payable and accrued liabilities		32,532	(3,783)	[2]	6,397	[2]
Income taxes payable		4,648	6,601	[2]	(4,861)	[2]
Long term tax payable		462	(3,478)	[2]	(1,082)	[2]
Other assets and liabilities, net		(3,008)	2,431	[2]	2,203	[2]
Net cash provided by operating activities		49,667	184,333	[2]	88,813	[2]
Investing Activities
Acquisitions, net of cash acquired		(17,798)	0	[2]	(400,784)	[2]
Purchase of property, plant and equipment		(25,263)	(17,874)	[2]	(31,337)	[2]
Proceeds from sale of property, plant and equipment		9,667	3,703	[2]	2,277	[2]
Purchase of patents		(44)	0	[2]	(96)	[2]
Net cash used in investing activities		(33,438)	(14,171)	[2]	(429,940)	[2]
Financing Activities
Borrowings on bank revolving credit facility		188,000	115,000	[2]	217,000	[2]
Repayment on bank revolving credit facility		(189,000)	(255,000)	[2]	(157,000)	[2]
Principal payments on long-term debt and capital leases		(15,093)	(18,867)	[2]	(122)	[2]
Proceeds from issuance of long-term debt		0	0	[2]	300,002	[2]
Debt issuance cost		0	0	[2]	(2,875)	[2]
Dividends paid		(6,627)	(6,124)	[2]	(5,626)	[2]
Proceeds from exercise of stock options		1,676	1,459	[2]	2,573	[2]
Treasury stock repurchased		0	0	[2]	(4,140)	[2]
Common stock repurchased		(1,957)	(710)	[2]	(589)	[2]
Net cash used in financing activities		(23,001)	(164,242)	[2]	349,223	[2]
Effect of exchange rate changes on cash		(1,308)	1,964	[2]	172	[2]
Net change in cash and cash equivalents		(8,080)	7,884	[2]	8,268	[2]
Cash and cash equivalents at beginning of the year	[2]	50,195	42,311		34,043
Cash and cash equivalents at end of the year		42,115	50,195	[2]	42,311	[2]
Cash paid during the year for:
Interest		10,248	17,049	[2]	9,455	[2]
Income taxes		$ 32,865	$ 17,140	[2]	$ 23,099	[2]

[1] Years ended December 31, 2020 and 2019 amounts have been adjusted to reflect the change in inventory accounting method, as described in Note 1 to the Consolidated Financial Statements. 

[2] Years ended December 31, 2020 and 2019 amounts have been adjusted to reflect the change in inventory accounting method, as described in Note 1 to the Consolidated Financial Statements.