Condensed Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
Sales	$ 1,671.4	$ 2,321.7	$ 5,218.4	$ 7,399.2
Operating expenses:
Cost of goods sold	1,402.3	1,840.9	4,236.6	5,599.8
Selling and administration	90.9	92.7	303.9	296.0
Restructuring charges	11.9	7.6	92.0	14.3
Other operating (expense) income	(0.3)	13.0	27.2	16.3
Operating income	166.0	393.5	613.1	1,505.4
Interest expense	46.2	36.0	133.9	103.4
Interest income	1.0	0.5	3.2	1.2
Non-operating pension income	5.9	9.9	17.0	29.0
Income before taxes	126.7	367.9	499.4	1,432.2
Income tax provision	22.2	52.7	96.2	301.9
Net income	104.5	315.2	403.2	1,130.3
Net income (loss) attributable to noncontrolling interests	0.4	0.0	(4.1)	0.0
Net income attributable to Olin Corporation	$ 104.1	$ 315.2	$ 407.3	$ 1,130.3
Net income attributable to Olin Corporation per common share:
Basic	$ 0.84	$ 2.23	$ 3.19	$ 7.62
Diluted	$ 0.82	$ 2.18	$ 3.12	$ 7.44
Average common shares outstanding:
Basic	124.2	141.2	127.5	148.3
Diluted	127.0	144.3	130.6	151.9