Fresh Start Accounting - Footnotes (Details) - USD ($) $ in Millions	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 13, 2019	Dec. 31, 2020	Dec. 12, 2019
Fresh-Start Adjustment [Line Items]
Inventories		$ 987		$ 1,071
Accrued income taxes		214		214
Fresh-Start Adjustment, Increase (Decrease), Property and Equipment, Gross		2,127		7,445
Net change in cash and cash equivalents		(493)		(641)
Restricted cash		261		398
Net change in other non-current assets		388		336
Fresh-Start Adjustment, Increase (Decrease), Other Current Liabilities		557		618
Liabilities subject to compromise		0		7,634
Cancellation of predecessor common stock				1
Net change in accumulated deficit				(10,682)
Intangible assets, net		1,123		166
Fresh-Start Adjustment, Increase (Decrease), Accumulated Depreciation and Amortization		0		(5,607)
Property, plant, and equipment, net		2,127		1,838
Debtor Reorganization Items, Discharge of Claims and Liabilities	$ 0	4,297	$ 0
Unsecured Debt [Member] | Exit Notes, 11.00 Percent Due 2024 [Member]
Fresh-Start Adjustment [Line Items]
Stated interest rate on debt	11.00%
Unsecured Debt [Member] | Exit Notes, Rights Offering Notes
Fresh-Start Adjustment [Line Items]
Face amount of debt	$ 1,600
Unsecured Debt [Member] | Exit Notes, Takeback Notes
Fresh-Start Adjustment [Line Items]
Face amount of debt	500
Developed technology
Fresh-Start Adjustment [Line Items]
Intangible assets, net		728		74
Customer relationships
Fresh-Start Adjustment [Line Items]
Intangible assets, net		0		39
Trade Names
Fresh-Start Adjustment [Line Items]
Intangible assets, net		395		0
Other Intangible Assets [Member]
Fresh-Start Adjustment [Line Items]
Intangible assets, net		0		53
Reorganization Adjustments
Fresh-Start Adjustment [Line Items]
Inventories				0
Fresh-Start Adjustment, Proceeds From Exit Senior Notes		1,600
Transfers from restricted cash for the return of cash collateral (for letters of credit)		(167)
Payment of debtor in possession financing principal and interest		(1,531)
Fresh-Start Adjustment, Payments For Amended And Restated Credit Agreement, Principal And Interest		(306)
Fresh-Start Adjustment, Payments To Escrow For Remaining Professional Fees		30
Fresh-Start Adjustment, Payments For Deferred Financing Fees		22
Fresh-Start Adjustment, Payments For Other Liabilities		(18)
Payment of professional fees		(8)
Net change in cash and cash equivalents		(148)		148
Restricted cash		(137)		(137)
Fresh-Start Adjustment, Increase (Decrease) In Other Current Assets To Deferred Financing Fees On The Exit Financing Facilities		4
Fresh-Start Adjustment, Increase (Decrease) In Write-Off Of Deferred Financing Fees On The Amended And Restated Credit Agreement		(2)
Net change in other non-current assets		25		25
Payment of debtor in possession financing interest		(3)
Fresh-Start Adjustment, Payments For Amended And Restated Credit Agreement, Interest		(1)
Fresh-Start Adjustment, Increase (Decrease), Other Current Liabilities		(22)		(22)
Liabilities subject to compromise		7,634		(7,634)
Fresh-Start Adjustment, Increase (Decrease) In Issuance Of Common Stock To Creditors		(2,837)
Fresh-Start Adjustment, Increase (Decrease) In Issuance Of Take-Back Debt To Creditors		(500)
Gain on Settlement of Liabilities Subject to Compromise			$ 4,297
Cancellation of predecessor preferred stock		24		(24)
Cancellation of predecessor common stock				(1)
Fresh-Start Adjustment, Issuance Of Successor Common Stock To Creditors	2,837
Fresh-Start Adjustment, Issuance Of Common Stock To Former Stockholders	(29)			(29)
Fresh-Start Adjustment, Issuance Of Warrants	(31)			(31)
Capital in excess of par value				(35)
Net change in successor common stock	$ 2,897
Net change in accumulated deficit		4,271		4,271
Intangible assets, net				0
Property, plant, and equipment, net				0
Fresh-Start Adjustment, Increase (Decrease) In Accrual of Deferred Financing Fees On Exit Financing Facilities		1
Fresh-Start Adjustment, Increase (Decrease) In Write-Off Of Deferred Financing Fees On The Amended And Restated Credit Agreement		(2)
Fresh Start Adjustments
Fresh-Start Adjustment [Line Items]
Inventories				(84)
Fresh-Start Adjustment, Increase (Decrease), Deferred Costs, Current				10
Accrued income taxes				4
Net change in cash and cash equivalents				0
Restricted cash				0
Net change in other non-current assets				27
Fresh-Start Adjustment, Increase (Decrease), Other Current Liabilities				(39)
Cancellation of predecessor common stock				0
Capital in excess of par value				(6,698)
Net change in accumulated deficit				6,411
Intangible assets, net				957
Fresh-Start Adjustment, Increase (Decrease) In Noncurrent Right-Of-Use Assets				13
Property, plant, and equipment, net				289
Fresh-Start Adjustment, Increase (Decrease), Deferred Income Tax Assets, Noncurrent				14
Fresh-Start Adjustment, Increase (Decrease), Current Maturities of Capital Lease Obligations				5
Fresh-Start Adjustment, Increase (Decrease) In Intangible Liabilities, Current				15
Fresh-Start Adjustment, Increase (Decrease) In Operating Lease Liabilities, Noncurrent				22
Fresh-Start Adjustment, Increase (Decrease) In Intangible Liabilities, Noncurrent				7
Fresh-Start Adjustment, Increase (Decrease), Deferred Income Tax Liabilities, Noncurrent				43
Raw Materials [Member]
Fresh-Start Adjustment [Line Items]
Inventories		78		78
Work In Process [Member]
Fresh-Start Adjustment [Line Items]
Inventories		51		55
Finished Goods [Member]
Fresh-Start Adjustment [Line Items]
Inventories		858		938
Land, Buildings and Improvements [Member]
Fresh-Start Adjustment [Line Items]
Fresh-Start Adjustment, Increase (Decrease), Property and Equipment, Gross		569		1,205
Rental and service equipment [Member]
Fresh-Start Adjustment [Line Items]
Fresh-Start Adjustment, Increase (Decrease), Property and Equipment, Gross		1,280		4,697
Machinery and other [Member]
Fresh-Start Adjustment [Line Items]
Fresh-Start Adjustment, Increase (Decrease), Property and Equipment, Gross		$ 278		$ 1,543