Summary Of Major Accounting Policies Long-lived asset impairments (Details)	3 Months Ended
	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Impaired Long-Lived Assets Held and Used [Line Items]
Write-off Equipment and Intangibles	$ 7,300,000	$ 45,000,000
Impairment property plant equipment	51,578,000	143,000,000
Intangible Assets Impairments	477,000
Right-of-use asset impairment	16,708,000
Impairment of Long-Lived Assets Held-for-use	$ 68,763,000	$ 17,000,000
Weighted Average [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Alternative Investment, Measurement Input	0.12
weighted average member low range [Member] [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Alternative Investment, Measurement Input	0.15
Measurement Input, Long-term Revenue Growth Rate [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Alternative Investment, Measurement Input	0.02
Oceaneering AGV System [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	$ 145,000
Intangible Assets Impairments	310,000
Right-of-use asset impairment	695,000
Impairment of Long-Lived Assets Held-for-use	1,150,000
Oceaneering Entertainment System [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	1,593,000
Right-of-use asset impairment	3,472,000
Impairment of Long-Lived Assets Held-for-use	5,065,000
Global Data Solution [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Intangible Assets Impairments	167,000
Impairment of Long-Lived Assets Held-for-use	167,000
Ecosse [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	3,628,000
Intangible Assets Impairments	0
Right-of-use asset impairment	0
Impairment of Long-Lived Assets Held-for-use	3,628,000
Shallow Water [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	3,894,000
Intangible Assets Impairments	0
Right-of-use asset impairment	0
Impairment of Long-Lived Assets Held-for-use	3,894,000
Subsea Products Angola [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	25,941,000
Right-of-use asset impairment	12,541,000
Impairment of Long-Lived Assets Held-for-use	38,482,000
SDS Brazil [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	9,834,000
Impairment of Long-Lived Assets Held-for-use	9,834,000
SDS Rosyth [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment property plant equipment	6,543,000
Impairment of Long-Lived Assets Held-for-use	$ 6,543,000