Earnings Per Common Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Common Share
Net Income Attributable to Lannett Company, Inc	$ 44,811	$ 16,566	$ 79,743	$ 10,571
Basic weighted average common shares outstanding	35,669,904	34,677,426	35,633,917	32,131,831
Effect of potentially dilutive stock options and restricted stock awards	1,404,120	1,598,900	1,391,750	1,429,623
Diluted weighted average common shares outstanding	37,074,024	36,276,326	37,025,667	33,561,454
Earnings per common share attributable to Lannett Company, Inc.:
Basic (in dollars per share)	$ 1.26	$ 0.48	$ 2.24	$ 0.33
Diluted (in dollars per share)	$ 1.21	$ 0.46	$ 2.15	$ 0.31
Anti-dilutive shares excluded in the computation of diluted earnings per share	507,000	6,000	508,000	6,000