Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Earnings Per Common Share
Net Income attributable to Lannett common shareholders	$ 2,881	$ 609	$ 5,807	$ 815
Weighted average common shares outstanding (basic)	28,347,464	28,526,658	28,312,989	28,479,195
Effect of potentially dilutive options and restricted stock awards (in shares)	103,133	246,819	111,038	254,240
Weighted average common shares outstanding (diluted)	28,450,597	28,773,477	28,424,027	28,733,435
Basic earnings per common share (in dollars per share)	$ 0.10	$ 0.02	$ 0.21	$ 0.03
Diluted earnings per common share (in dollars per share)	$ 0.10	$ 0.02	$ 0.20	$ 0.03
Anti-dilutive shares excluded in the computation of diluted earnings per share	2,331,000	1,877,000	2,323,000	1,560,000