Condensed Consolidated Income Statements - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 245,346	$ 227,401	$ 814,054	$ 679,441
Operating expenses:
Costs of services	33,053	33,461	112,743	94,093
Cost of inventory sold	74,341	72,476	231,834	207,603
Selling, general and administrative expenses	88,323	85,335	287,052	230,287
Acquisition-related costs	2,007	3,587	5,039	35,162
Depreciation and amortization expenses	16,723	14,837	49,451	37,047
Gain on disposition of property, plant and equipment	(342)	(42)	(958)	(1,071)
Impairment loss				8,911
Foreign exchange loss (gain)	47	816	31	(7)
Total operating expenses	214,152	210,470	685,192	612,025
Operating income	31,194	16,931	128,862	67,416
Interest expense	(10,473)	(10,558)	(32,720)	(27,311)
Other income, net	7,182	592	8,995	6,346
Income before income taxes	27,903	6,965	105,137	46,451
Income tax expense (recovery)	4,791	(3,358)	19,091	7,982
Net income	23,112	10,323	86,046	38,469
Net income (loss) attributable to:
Stockholders	23,138	10,261	85,993	38,273
Non-controlling interests	$ (26)	$ 62	$ 53	$ 196
Earnings per share attributable to stockholders:
Basic	$ 0.21	$ 0.10	$ 0.80	$ 0.36
Diluted	$ 0.21	$ 0.09	$ 0.79	$ 0.35
Weighted average number of shares outstanding:
Basic	108,365,427	107,120,618	107,811,391	106,993,358
Diluted	109,887,194	108,178,303	109,133,378	108,069,624
Service Revenues [Member]
Revenues:
Total revenues	$ 161,374	$ 145,938	$ 551,736	$ 442,066
Revenue from Inventory Sales [Member]
Revenues:
Total revenues	$ 83,972	$ 81,463	$ 262,318	$ 237,375