Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Common Share
Net Income Attributable to Lannett Company, Inc	$ 13,520	$ 44,811	$ 46,701	$ 79,743
Basic weighted average common shares outstanding	36,388,542	35,669,904	36,349,597	35,633,917
Effect of potentially dilutive options and restricted stock awards	999,908	1,404,120	1,052,281	1,391,750
Diluted weighted average common shares outstanding	37,388,450	37,074,024	37,401,878	37,025,667
Earnings per common share attributable to Lannett Company, Inc.:
Basic (in dollars per share)	$ 0.37	$ 1.26	$ 1.28	$ 2.24
Diluted (in dollars per share)	$ 0.36	$ 1.21	$ 1.25	$ 2.15
Anti-dilutive shares excluded in the computation of diluted earnings per share	2,600,000	507,000	2,600,000	508,000