Income Taxes - Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Aug. 01, 2022	Dec. 31, 2021
Deferred tax assets
Post-retirement and pension benefit costs	$ 725		$ 978
Net operating loss carryforwards	871		2,463
Other employee benefits	85		96
Other	519		554
Gross deferred tax assets	2,200		4,091
Less valuation allowance	(550)		(1,566)
Net deferred tax assets	1,650		2,525
Deferred tax liabilities
Property, plant and equipment, primarily due to depreciation differences	(3,046)		(3,941)
Goodwill and other intangible assets	(1,634)		(2,473)
Gross deferred tax liabilities	(4,680)		(6,414)
Net deferred tax liability	(3,030)		$ (3,889)
Disposal Group, Held-for-sale, Not Discontinued Operations | EMEA Business
Deferred tax liabilities
Deferred tax assets	138
Deferred tax liabilities	38
Disposal Group, Held-for-sale, Not Discontinued Operations | Latin American Business
Deferred tax liabilities
Deferred tax assets		$ 46
Deferred tax liabilities		$ 129
Disposal Group, Held-for-sale, Not Discontinued Operations | ILEC Business
Deferred tax liabilities
Net deferred tax liability	$ 0