Business Combination - Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition, Pro Forma Information [Abstract]
Net sales	$ 186,025	$ 151,788	$ 597,012	$ 494,381
Net (loss) income	$ (3,713)	$ (152,253)	$ 4,235	$ (182,267)
(Loss) Earnings per share: Basic	$ (0.16)	$ (8.99)	$ 0.19	$ (11.51)
(Loss) Earnings per share: Diluted	$ (0.16)	$ (8.99)	$ 0.19	$ (11.51)
Revenues	$ 186,025	$ 131,382	$ 555,095	$ 417,590
Perrigo Animal Health Acquisition
Business Acquisition, Pro Forma Information [Abstract]
Pre-tax net income			1,700
Perrigo Animal Health Acquisition \| Acquisition-related Costs [Member]
Business Acquisition, Pro Forma Information [Abstract]
Revenues			2,400
Perrigo Animal Health Acquisition \| Fair Value Adjustment to Inventory [Member]
Business Acquisition, Pro Forma Information [Abstract]
Revenues	$ 2,000		5,400
Product \| Perrigo Animal Health Acquisition
Business Acquisition, Pro Forma Information [Abstract]
Net sales			$ 16,600

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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-Section 50
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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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Amount after tax of pro forma income from continuing operations as if the business combination had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
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-Paragraph 2
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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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