CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net income (loss) attributable to Amphastar Pharmaceuticals, Inc.	$ (192)	$ 47,787	$ 3,757	$ 48,655
Other comprehensive income (loss) attributable to Amphastar Pharmaceuticals, Inc., net of income taxes
Foreign currency translation adjustment	288	(97)	(486)	(210)
Total other comprehensive income (loss) attributable to Amphastar Pharmaceuticals, Inc.	288	(97)	(486)	(210)
Total comprehensive income (loss) attributable to Amphastar Pharmaceuticals, Inc.	$ 96	$ 47,690	$ 3,271	$ 48,445