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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

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- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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Employee Equity-Based Compensation - Equity-Based Compensation Expense and Tax Benefit (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense		$ 3,465	$ 3,520	$ 12,476	$ 10,970
Unrecognized equity-based compensation cost		21,500		$ 21,500
Granted (shares)				1,355,371
Shares issuable upon the release of restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unrecognized equity-based compensation cost, restricted stock units		1,100		$ 1,100
Performance-based stock options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense		545		545
Granted (shares)	225,000
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense		68	22	172	44
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense		1,476	994	3,926	2,886
Sales, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense		$ 1,921	$ 2,504	8,378	8,040
Capitalized inventory
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense				380	262
Property and equipment
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Equity-based compensation expense				$ 170	$ 33