Interim Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 14,583	$ 12,167
Adjustment to reconcile net income to net cash used in operating activities:
Provision for doubtful accounts	(94)	(7)
Depreciation - Property, plant and equipment	3,135	2,777
Depreciation - Rental equipment	1,405	1,407
Amortization of intangibles	881	777
Amortization of debt issuance costs	55	55
Stock-based compensation expense	458	328
Deferred income tax expense (benefit)	930	(41)
Gain on sale of property, plant and equipment	(17)	(67)
Changes in operating assets and liabilities:
Accounts receivable	(27,998)	(25,048)
Inventories	(12,291)	(4,696)
Rental equipment	(5,663)	1,516
Prepaid expenses and other assets	(1,765)	358
Trade accounts payable and accrued liabilities	(1,483)	4,776
Income taxes payable	(386)	4,323
Other assets and long-term liabilities	104	(68)
Net cash used in operating activities	(28,146)	(1,443)
Investing Activities
Purchase of property, plant and equipment	(7,645)	(2,257)
Proceeds from sale of property, plant and equipment	97	74
Net cash used in investing activities	(7,548)	(2,183)
Financing Activities
Borrowings on bank revolving credit facility	90,000	66,000
Repayments on bank revolving credit facility	(3,000)	(9,000)
Proceeds from issuance of debt	0	460
Dividends paid	(1,276)	(1,146)
Proceeds from sale of common stock	266	606
Net cash provided by financing activities	85,990	56,920
Effect of exchange rate changes on cash and cash equivalents	181	575
Net change in cash and cash equivalents	50,477	53,869
Cash and cash equivalents at beginning of the period	25,373	16,793
Cash and cash equivalents at end of the period	75,850	70,662
Cash paid during the period for:
Interest	1,123	1,485
Income taxes	$ 5,066	$ 2,366