Business Combinations and Other Strategic Investments - Consideration Paid for Acquisition and the Fair Value of the Acquired Assets and Assumed Liabilities (Details) $ in Thousands, SFr in Millions			12 Months Ended
	Jan. 02, 2015 USD ($)	Jul. 22, 2014 CHF (SFr)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Recognized amounts of identifiable assets acquired:
Bargain purchase gain			$ 0	$ 0	$ (849)
Akorn AG, formerly Excelvision
Consideration:
Amount of cash paid	$ 25,900
Outstanding amount payable to Fareva	2,500
Total consideration at closing	28,400	SFr 21.7
Recognized amounts of identifiable assets acquired:
Cash and cash equivalents	1,200
Accounts receivable	3,400
Inventory	4,200
Other current assets	900
Property and equipment	26,600
Total assets acquired	36,300
Assumed current liabilities	(1,700)
Assumed non-current liabilities	(3,900)
Deferred tax liabilities	(1,400)
Total liabilities assumed	(7,000)
Bargain purchase gain	(900)
Fair value of assets acquired	$ 28,400