CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
Net revenues	$ 85,806	$ 79,047	$ 170,494	$ 158,837
Cost of revenues	52,629	46,660	100,494	95,547
Gross profit	33,177	32,387	70,000	63,290
Operating (income) expenses:
Selling, distribution, and marketing	4,026	2,992	7,320	6,133
General and administrative	15,924	12,426	26,670	28,753
Research and development	16,149	15,996	31,452	30,603
Total operating expenses	36,099	31,414	65,442	65,489
Income (loss) from operations	(2,922)	973	4,558	(2,199)
Non-operating (expenses) income:
Interest income	198	143	351	291
Interest expense	(35)	(24)	(111)	(54)
Other income (expenses), net	1,255	60,001	(497)	59,422
Total non-operating (expenses) income, net	1,418	60,120	(257)	59,659
Income (loss) before income taxes	(1,504)	61,093	4,301	57,460
Income tax provision (benefit)	(75)	14,173	2,205	12,694
Net income (loss)	(1,429)	46,920	2,096	44,766
Net loss attributable to non-controlling interests	(1,237)	(867)	(1,661)	(3,889)
Net income (loss) attributable to Amphastar Pharmaceuticals, Inc.	$ (192)	$ 47,787	$ 3,757	$ 48,655
Net income (loss) per share attributable to Amphastar Pharmaceuticals, Inc. shareholders:
Basic (in Dollars per share)	$ 0.00	$ 1.01	$ 0.08	$ 1.04
Diluted (in Dollars per share)	$ 0.00	$ 0.96	$ 0.08	$ 0.97
Weighted-average shares used to compute net income (loss) per share attributable to Amphastar Pharmaceuticals, Inc. shareholders:
Basic (in Shares)	46,753	47,107	46,581	46,925
Diluted (in Shares)	46,753	49,894	48,458	50,155