UNCONSOLIDATED JOINT VENTURE (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2011	Sep. 30, 2013	Dec. 31, 2010	Sep. 30, 2013 Strides Arcolab Limited [Member]	Mar. 31, 2013 Akorn-Strides LLC [Member]	Sep. 30, 2013 Akorn-Strides LLC [Member]	Dec. 31, 2012 Akorn-Strides LLC [Member]
Schedule of Equity Method Investments [Line Items]
Joint venture ownership percentage (in hundredths)		50.00%		50.00%
Joint venture sale of rights		$ 35.0		$ 28.2		$ 63.2
Joint venture gain on sale of rights	24.2	63.1	38.9
Joint Venture Company summarized financial information [Abstract]
Cash						0.6	0.8
Total liabilities						0.1	0.4
Partners' equity						0.5	0.4
Adjustment to reserve for product returns					$ 0.2