Segment Information Narrative (Details) $ in Millions	1 Months Ended	3 Months Ended								11 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 13, 2019 USD ($)	Dec. 31, 2019 USD ($) unit	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Revenues	$ 261	$ 985	$ 1,314	$ 1,309	$ 1,346	$ 1,429	$ 1,444	$ 1,448	$ 1,423	$ 4,954	$ 4,954	$ 5,744	$ 5,699
Number of Reportable Segments | unit											2
Goodwill, Impairment Loss	0		$ 399	102	229	1,900				730		1,917	0
Long-Lived Asset Impairments	0									20		151	928
Asset Impairment Charges											$ 20
Accounts Receivable, Allowance for Credit Loss, Writeoff	0									0		0	230
Restructuring Charges	0			61						189		126	183
Assets	7,293	7,293				6,601					7,293	6,601
Deferred tax assets for long-lived assets	39	39				35					39	35
UNITED STATES
Segment Reporting Information [Line Items]
Revenues													1,600
Assets	1,200	1,200				1,600					1,200	1,600
2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges													183
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss										730		1,917
Restructuring Charges										189		(126)	183	[1]
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	261									4,954		5,744	5,699
Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges													740
Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss										508		1,380
Asset Impairment Charges				$ 13									135
Assets	2,514	2,514				3,122					2,514	3,122
Western Hemisphere [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges													70
Western Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	121									2,620		3,063	2,937
Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss										222		537
Asset Impairment Charges					$ 7								37
Assets	4,392	4,392				2,966					4,392	2,966
Eastern Hemisphere [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges													77
Eastern Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	140									$ 2,334		2,681	2,762
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 387	$ 387				$ 513					$ 387	513
Corporate, Non-Segment [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges													36
Assets, Total [Member]
Segment Reporting Information [Line Items]
Long-Lived Asset Impairments												$ 87	$ 506

[1] (j) Includes restructuring charges of $183 million: $70 million in the Western Hemisphere, $77 million in the Eastern Hemisphere and $36 million in Corporate.