SEGMENT REPORTING - Revenue (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($) brand productFamily	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) productFamily segment reportingUnit brand	Sep. 30, 2024 USD ($)
Segment reporting
Number of operating segments | segment			2
Number of reporting units | segment			3
Established brand products | brand	20		20
Product families | productFamily	100		100
Net Revenues	$ 227,813	$ 148,332	$ 636,306	$ 423,802
Cost of sales (excluding depreciation and amortization)	93,389	63,075	241,041	169,930
Research and development expense	12,304	10,128	39,403	27,935
Selling, general, and administrative	76,656	79,075	234,955	179,917
Depreciation and amortization	22,632	15,748	68,804	45,131
Contingent consideration fair value adjustment	(14,470)	825	(25,285)	1,274
Loss (gain) on disposal of assets	295	0	295	(5,347)
Intangible asset impairment charge	767	0	767	0
Operating income (loss)	36,240	(20,519)	76,326	4,962
Unrealized gain on investment in equity securities	3,140	1,355	2,551	8,298
Interest expense, net	(4,727)	(2,331)	(15,649)	(11,587)
Other (expense)income , net	(853)	(2,535)	1,084	(2,655)
Loss on extinguishment of debt	0	(7,468)	0	(7,468)
Income (Loss) Before Income Tax Expense (Benefit)	33,800	(31,498)	$ 64,312	(8,450)
Rare Disease and Brands
Segment reporting
Number of reporting units | reportingUnit			2
Operating Segments | Generics and Other
Segment reporting
Net Revenues	98,688	82,711	$ 295,941	236,346
Cost of sales (excluding depreciation and amortization)	53,736	42,585	143,468	121,399
Research and development expense	8,472	6,123	26,474	19,569
Selling, general, and administrative	1,405	1,384	4,202	3,737
Depreciation and amortization	0	0	0	0
Contingent consideration fair value adjustment	0	0	0	0
Loss (gain) on disposal of assets	0		0	0
Intangible asset impairment charge	0		0
Operating income (loss)	35,075	32,619	121,797	91,641
Unrealized gain on investment in equity securities	0	0	0	0
Interest expense, net	0	0	0	0
Other (expense)income , net	0	0	0	0
Loss on extinguishment of debt				0
Income (Loss) Before Income Tax Expense (Benefit)	35,075	32,619	121,797	91,641
Operating Segments | Rare Disease and Brands
Segment reporting
Net Revenues	129,125	65,621	340,365	187,456
Cost of sales (excluding depreciation and amortization)	39,653	20,490	97,573	48,531
Research and development expense	3,832	4,005	12,929	8,366
Selling, general, and administrative	43,983	35,705	137,610	86,720
Depreciation and amortization	0	0	0	0
Contingent consideration fair value adjustment	0	0	0	0
Loss (gain) on disposal of assets	0		0	0
Intangible asset impairment charge	0		0
Operating income (loss)	41,657	5,421	92,253	43,839
Unrealized gain on investment in equity securities	0	0	0	0
Interest expense, net	0	0	0	0
Other (expense)income , net	0	0	0	0
Loss on extinguishment of debt				0
Income (Loss) Before Income Tax Expense (Benefit)	41,657	5,421	92,253	43,839
Corporate and Unallocated
Segment reporting
Net Revenues	0	0	0	0
Cost of sales (excluding depreciation and amortization)	0	0	0	0
Research and development expense	0	0	0	0
Selling, general, and administrative	31,268	41,986	93,143	89,460
Depreciation and amortization	22,632	15,748	68,804	45,131
Contingent consideration fair value adjustment	(14,470)	825	(25,285)	1,274
Loss (gain) on disposal of assets	295		295	(5,347)
Intangible asset impairment charge	767		767
Operating income (loss)	(40,492)	(58,559)	(137,724)	(130,518)
Unrealized gain on investment in equity securities	3,140	1,355	2,551	8,298
Interest expense, net	(4,727)	(2,331)	(15,649)	(11,587)
Other (expense)income , net	(853)	(2,535)	1,084	(2,655)
Loss on extinguishment of debt				(7,468)
Income (Loss) Before Income Tax Expense (Benefit)	$ (42,932)	$ (69,538)	$ (149,738)	$ (143,930)