Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Common Share
Net Income attributable to Lannett common shareholders	$ 3,947	$ 1,718	$ 9,754	$ 2,533
Basic weighted average common shares outstanding	28,490,175	28,571,062	28,371,189	28,509,595
Effect of potentially dilutive options and restricted stock awards (in shares)	625,766	148,607	273,642	158,686
Diluted weighted average common shares outstanding	29,115,941	28,719,669	28,644,831	28,668,281
Basic earnings per common share (in dollars per share)	$ 0.14	$ 0.06	$ 0.34	$ 0.09
Diluted earnings per common share (in dollars per share)	$ 0.14	$ 0.06	$ 0.34	$ 0.09
Anti-dilutive shares excluded in the computation of diluted earnings per share	265,000	2,307,000	1,488,000	2,307,000