LEASES (Details 4) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2023	$ 81.8
2024	68.1
2025	58.4
2026	45.4
2027	35.3
Thereafter	138.3
Total lease payments	427.3
Less: Imputed interest(1)	(63.0)
Present value of operating lease liabilities	364.3
Finance Lease, Liability, Payment, Due [Abstract]
2023	1.0
2024	0.8
2025	0.2
2026	0.0
2027	0.0
Thereafter	0.0
Total lease payments	2.0
Less: Imputed interest(1)	(0.1)
Finance lease obligations	1.9	$ 3.0
Total Lease Liability, Payments, Due [Abstract]
2023	82.8
2024	68.9
2025	58.6
2026	45.4
2027	35.3
Thereafter	138.3
Total lease payments	429.3
Less: Imputed interest(1)	(63.1)
Present value of lease liabilities	$ 366.2	$ 381.8

The total of operating and finance lease liabilities included in the balance sheet.

No definition available.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases.

+ References

No definition available.

+ Details

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- Definition

Total Lease Liability, Payments, Due.

+ References

No definition available.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in next fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in fifth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

TotAmount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in fourth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in third fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due in second fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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Namespace Prefix:	oln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases, due after fifth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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Namespace Prefix:	oln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating and finance leases.

+ References

No definition available.

+ Details

Name:	oln_TotalLeaseLiabilityUndiscountedExcessAmount
Namespace Prefix:	oln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- References

No definition available.

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Namespace Prefix:	us-gaap_
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Balance Type:	na
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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918701-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments for finance lease.

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
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- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for finance lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for finance lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease.

+ References

+ Details

Name:	us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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- References

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=123391704&loc=SL77918627-209977

+ Details

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