CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Treasury Stock	Stockholders' Equity Attributable to Lannett Co., Inc	Noncontrolling Interest	Total
Balance at Jun. 30, 2015	$ 37	$ 236,178	$ 233,573	$ (295)	$ (6,080)	$ 463,413	$ 353	$ 463,766
Balance (in shares) at Jun. 30, 2015	36,783
Increase (Decrease) in Shareholders' Equity
Shares issued in connection with share-based compensation plans		4,134				4,134		4,134
Shares issued in connection with share-based compensation plans (in shares)	367
Share-based compensation		11,562				11,562		11,562
Excess tax benefits on share-based compensation awards		1,507				1,507		1,507
Purchase of treasury stock					(1,269)	(1,269)		(1,269)
Issuance of warrant		29,920				29,920		29,920
Distribution to noncontrolling interests							(20)	(20)
Net income (loss)			44,782			44,782	75	44,857
Balance at Jun. 30, 2016	$ 37	283,301	278,355	(295)	(7,349)	554,049	408	554,457
Balance (in shares) at Jun. 30, 2016	37,150
Increase (Decrease) in Shareholders' Equity
Shares issued in connection with share-based compensation plans		2,818				2,818		2,818
Shares issued in connection with share-based compensation plans (in shares)	378
Share-based compensation		7,719				7,719		7,719
Purchase of noncontrolling interest		(1,058)				(1,058)	(442)	(1,500)
Purchase of treasury stock					(1,898)	(1,898)		(1,898)
Other comprehensive income , net of income tax				73		73		73
Net income (loss)			(581)			(581)	$ 34	(547)
Balance at Jun. 30, 2017	$ 37	292,780	277,774	(222)	(9,247)	561,122		561,122
Balance (in shares) at Jun. 30, 2017	37,528
Increase (Decrease) in Shareholders' Equity
Shares issued in connection with share-based compensation plans	$ 1	4,141				4,142		4,142
Shares issued in connection with share-based compensation plans (in shares)	729
Share-based compensation		9,896				9,896		9,896
Purchase of treasury stock					(4,642)	(4,642)		(4,642)
Other comprehensive income , net of income tax				(293)		(293)		(293)
Net income (loss)			28,690			28,690		28,690
Balance at Jun. 30, 2018	$ 38	$ 306,817	$ 306,464	$ (515)	$ (13,889)	$ 598,915		$ 598,915
Balance (in shares) at Jun. 30, 2018	38,257