Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Unrecognized cost of unvested share-based compensation awards.

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Amount of other income tax expense (benefit).

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Employee and Consultant Equity-Based Compensation - Equity-Based Compensation Expense and Tax Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 13,933	$ 8,775	$ 8,388
Recognized tax benefit	0	0	0
Unrecognized equity-based compensation cost	15,900
Cumulative impact of accounting change for forfeitures		(655)
Additional deferred tax asset related to stock options	8,195	7,208
ASU 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional deferred tax asset related to stock options				$ 1,500
RSU's
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized equity-based compensation cost	174
Accumulated Deficit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative impact of accounting change for forfeitures		(655)
Accumulated Deficit \| ASU 2016-09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative impact of accounting change for forfeitures				$ 655
Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	99	0	0
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	3,738	1,585	2,479
Sales, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	10,096	$ 7,190	$ 5,909
Capitalized inventory
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	304
Property and equipment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 48