Revenue Performance obligation (Details) $ in Millions	Jun. 30, 2018 USD ($)
Revenue Recognition [Abstract]
Revenue Recognition for Remaining Performance Obligations	$ 247
Price Allocated to Remaining Performance Obligations	$ 295

Revenue to be recognized for the remaining performance obligations over next 12 months

No definition available.

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