Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Earnings (Loss) Per Common Share
Net income (loss) attributable to Lannett Company, Inc.	$ 8,172	$ 13,520	$ (21,236)	$ 46,701
Basic weighted average common shares outstanding	36,810,388	36,388,542	36,754,828	36,349,597
Effect of potentially dilutive stock options, warrants and restricted stock awards	865,982	999,908		1,052,281
Diluted weighted average common shares outstanding	37,676,370	37,388,450	36,754,828	37,401,878
Earnings (loss) per common share attributable to Lannett Company, Inc.:
Basic (in dollars per share)	$ 0.22	$ 0.37	$ (0.58)	$ 1.28
Diluted (in dollars per share)	$ 0.22	$ 0.36	$ (0.58)	$ 1.25
Anti-dilutive shares excluded in the computation of diluted earnings per share	3,000,000	2,600,000	4,400,000	2,600,000