Summary Of Major Accounting Policies - Acquisitions (Details)

3 Months Ended

12 Months Ended

Mar. 31, 2021

Dec. 31, 2021

Dec. 31, 2020

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

New Accounting Pronouncements and Changes in Accounting Principles [Text Block]

2. ACCOUNTING STANDARDS UPDATE

Recently Adopted Accounting Standards. On January 1, 2021, we adopted ASU No. 2019-12, “Simplifying the Accounting for Income Taxes” (“ASU 2019-12”), which simplifies the accounting for income taxes, eliminates certain exceptions within Accounting Standards Codification 740 (“ASC 740”), “Income Taxes,” and clarifies certain aspects of the current guidance to promote consistency among reporting entities. Most amendments within the standard are required to be applied on a prospective basis, while certain amendments must be applied on a retrospective or modified retrospective basis. Our adoption of ASU 2019-12 on January 1, 2021, did not have a material impact on our consolidated financial statements.

Recently Issued Accounting Standards.

Details of Impairment of Long-Lived Assets Held and Used by Asset [Table Text Block]

Our reporting units with long-lived asset impairments in the three-month period ended March 31, 2020, were realigned into our new reporting segments as follows:

		Three Months Ended March 31, 2020
(in thousands)		As originally recorded		As recast to reflect segment changes
Segment/Reporting Unit		Long-lived Asset Impairments		Manufactured Products		OPG		IMDS		Total
Subsea Products
	Subsea Distribution Solutions U.K.	$	6,543	$	6,543	$	—	$	—	$	6,543
	Subsea Distribution Solutions Brazil	9,834		9,834						9,834
	Subsea Distribution Solutions Angola	38,482		38,482						38,482
Subsea Projects
	Shallow Water vessels	3,894				3,894				3,894
	Renewables and Special Projects Group	3,628				3,628				3,628
	Global Data Solutions	167						167		167
Advanced Technologies
	Oceaneering Entertainment Systems	5,065		5,065						5,065
	Oceaneering AGV Systems	1,150		1,150						1,150
	Total long-lived asset impairments	$	68,763	$	61,074	$	7,522	$	167	$	68,763

In 2020, we also recorded $24 million for write-downs and write-offs of certain equipment and intangible assets associated with equipment obsolescence.

Our reporting units with long-lived asset impairments in the year ended December 31, 2019, were realigned into our new reporting segments as follows:

		Year Ended December 31, 2019
(in thousands)		As originally recorded		As recast to reflect segment changes
Segment/Reporting Unit		Long-lived Asset Impairments		OPG		IMDS		Total
Subsea Projects
	Deepwater and Shallow Water vessel asset groups	$	131,894	$	131,894			$	131,894
	Ecosse asset group	10,721		10,721				10,721
Asset Integrity		16,738				16,738		16,738
	Total long-lived asset impairments	$	159,353	$	142,615	$	16,738	$	159,353