Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Partnership interest in Amneal	$ 212,402	$ 226,049
Projected imputed interest on TRA	25,539	25,278
Net operating loss carryforward	77,255	119,088
IRC Section 163(j) interest carryforward	45,425	44,978
Capitalized costs	1,502	0
Accrued expenses	410	304
Intangible assets	28,400	31,677
Tax credits and other	31,879	22,819
Total deferred tax assets	422,812	470,193
Valuation allowance	(422,812)	(470,193)	$ (41,235)	$ (41,617)
Net deferred tax assets	$ 0	$ 0