Condensed Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Measurement Input, Expected Dividend Rate	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2023			$ 120.2	$ 24.8	$ (496.3)	$ 2,583.7
Common stock repurchased and retired	$ (105.4)		(2.0)	(37.3)		(66.1)
Stock Issued During Period, Value, Stock Options Exercised	19.8		0.8	19.0
Common stock issued for other transactions			0.4	(4.3)
Stock-based compensation				(2.2)
Other comprehensive income, net of tax	6.6				6.6
Common stock dividends paid						(23.9)
Balance at end of period at Mar. 31, 2024	2,172.0		119.4	0.0	(489.7)	2,542.3
Net income attributable to Olin Corporation	48.6					48.6
Balance at beginning of period at Dec. 31, 2023							$ 35.9
Net loss attributable to noncontrolling interests	(0.8)						(0.8)
Balance at end of period at Mar. 31, 2024	35.1						35.1
Dividends declared per share of common stock		$ 0.20
Total equity	2,207.1
Total equity	2,055.4
Balance at beginning of period at Dec. 31, 2024	2,023.1		115.7	0.0	(450.1)	2,357.5
Common stock repurchased and retired	(20.2)		(0.7)	(5.1)		(14.4)
Stock Issued During Period, Value, Stock Options Exercised	1.9		0.0	1.9
Common stock issued for other transactions			0.1	3.9
Stock-based compensation				(0.7)
Other comprehensive income, net of tax	19.5				19.5
Common stock dividends paid						(23.0)
Balance at end of period at Mar. 31, 2025	2,006.0		$ 115.1	$ 0.0	$ (430.6)	2,321.5
Net income attributable to Olin Corporation	1.4					$ 1.4
Balance at beginning of period at Dec. 31, 2024	32.3						32.3
Net loss attributable to noncontrolling interests	(0.2)						(0.2)
Balance at end of period at Mar. 31, 2025	32.1						$ 32.1
Dividends declared per share of common stock		$ 0.20
Total equity	$ 2,038.1