Revenue Recognition - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Product revenue	$ 74,970	$ 74,617
Service revenue	9,489	0
Total revenue	84,459	74,617
Product cost of goods sold	34,832	29,738
Service cost of goods sold	3,409	0
Cost of goods sold	38,241
Gross profit	$ 46,218	44,879
Gross profit percentage	54.70%
Selling expenses	$ 21,940	24,804
General and administrative expenses	22,441	19,363
Operating expenses	44,381	44,167
Operating income	1,837	712
Calculated under Revenue Guidance in Effect before Topic 606
Disaggregation of Revenue [Line Items]
Product revenue	84,634
Service revenue	0
Total revenue	84,634
Product cost of goods sold	34,832
Service cost of goods sold	0
Cost of goods sold	34,832
Gross profit	$ 49,802
Gross profit percentage	58.80%
Selling expenses	$ 25,486
General and administrative expenses	22,441
Operating expenses	47,927
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Disaggregation of Revenue [Line Items]
Product revenue	9,664
Service revenue	(9,489)
Total revenue	175
Product cost of goods sold	0
Service cost of goods sold	(3,409)
Cost of goods sold	(3,409)
Gross profit	3,584
Selling expenses	3,546
General and administrative expenses	0
Operating expenses	3,546
UNITED STATES
Disaggregation of Revenue [Line Items]
Total revenue	68,318	67,281
CANADA
Disaggregation of Revenue [Line Items]
Total revenue	$ 16,141	$ 7,336