Line of Credit Facility, Available Additional Borrowing Capacity

No definition available.

Name:	oii_LineOfCreditFacilityAvailableAdditionalBorrowingCapacity
Namespace Prefix:	oii_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Basis Spread on Variable Rate

+ References

No definition available.

+ Details

Name:	oii_LineOfCreditFacilityBasisSpreadOnVariableRate
Namespace Prefix:	oii_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow for loan and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

Name:	us-gaap_PaymentsOfFinancingCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=oii_CreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_AdvanceTypeAxis=oii_AdjustedBaseRateAdvancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_InterestRateComponentAxis=oii_AdjustedBaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_BaseRateTypeAxis=oii_FederalFundsRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_BaseRateTypeAxis=oii_EurodollarRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_InterestRateComponentAxis=oii_ApplicableMarginMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	oii_AdvanceTypeAxis=oii_EurodollarAdvancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Line of Credit (Details) - USD ($) $ in Millions	3 Months Ended
Debt - Line of Credit (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2014
Line of Credit Facility [Line Items]
Line of Credit Facility, Available Additional Borrowing Capacity	$ 300.0
Payments of Financing Costs		$ 2.6
Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.125%
Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.30%
Line of Credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 500.0
Credit Agreement [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300.0
Credit Agreement [Member] \| Adjusted Base Rate Advances [Member] \| Adjusted Base Rate [Member] \| Federal Funds Rate [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	0.50%
Credit Agreement [Member] \| Adjusted Base Rate Advances [Member] \| Adjusted Base Rate [Member] \| Eurodollar Rate [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	1.00%
Credit Agreement [Member] \| Adjusted Base Rate Advances [Member] \| Applicable Margin [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	0.125%
Credit Agreement [Member] \| Adjusted Base Rate Advances [Member] \| Applicable Margin [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	0.75%
Credit Agreement [Member] \| Eurodollar Advances [Member] \| Applicable Margin [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	1.125%
Credit Agreement [Member] \| Eurodollar Advances [Member] \| Applicable Margin [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Basis Spread on Variable Rate	1.75%