Planned Divestiture of the Latin American and ILEC Businesses - Components of Held for Sale Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Aug. 03, 2021	Dec. 31, 2020	Dec. 31, 2019
Assets held for sale
Cash and cash equivalents	$ 40		$ 0	$ 0
Other current assets	126
Defined Benefit Plan, Funded Plan
Liabilities held for sale
Pension liability	2,500
Defined Benefit Plan, Funded through Transfer of Plan Assets
Liabilities held for sale
Pension liability	$ 2,200
Funded percentage	88.00%
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets held for sale
Cash and cash equivalents	$ 40
Accounts receivable, less allowance of $3, $21 and $24	310
Other current assets	126
Property, plant and equipment, net accumulated depreciation of $434, $8,303 and $8,737	5,082
Goodwill	2,854
Other intangible assets, net	284
Other non-current assets	113
Total assets held for sale	8,809
Liabilities held for sale
Accounts payable	165
Salaries and benefits	48
Income and other taxes	51
Interest	10
Current portion of deferred revenue	116
Other current liabilities	42
Long-term debt, net of discounts	1,377
Deferred income taxes, net	129
Pension and other post-retirement benefits	58
Other non-current liabilities	261
Total liabilities held for sale	2,257
Allowance for doubtful accounts	24
Accumulated depreciation	8,737
Long-term finance lease obligations	57
Disposal Group, Held-for-sale, Not Discontinued Operations | Senior notes | Embarq Corporation
Liabilities held for sale
Long-term debt, net of discounts	1,400
Unamortized discount	117
Disposal Group, Held-for-sale, Not Discontinued Operations | Latin American Business
Assets held for sale
Cash and cash equivalents	39
Accounts receivable, less allowance of $3, $21 and $24	83
Other current assets	81
Property, plant and equipment, net accumulated depreciation of $434, $8,303 and $8,737	1,591
Goodwill	239
Other intangible assets, net	126
Other non-current assets	75
Total assets held for sale	2,234
Liabilities held for sale
Accounts payable	101
Salaries and benefits	23
Income and other taxes	27
Interest	0
Current portion of deferred revenue	26
Other current liabilities	7
Long-term debt, net of discounts	0
Deferred income taxes, net	129
Pension and other post-retirement benefits	2
Other non-current liabilities	120
Total liabilities held for sale	435
Allowance for doubtful accounts	3
Accumulated depreciation	434
Disposal Group, Held-for-sale, Not Discontinued Operations | ILEC Business
Assets held for sale
Cash and cash equivalents	1
Accounts receivable, less allowance of $3, $21 and $24	227
Other current assets	45
Property, plant and equipment, net accumulated depreciation of $434, $8,303 and $8,737	3,491
Goodwill	2,615
Other intangible assets, net	158
Other non-current assets	38
Total assets held for sale	6,575
Liabilities held for sale
Accounts payable	64
Salaries and benefits	25
Income and other taxes	24
Interest	10
Current portion of deferred revenue	90
Other current liabilities	35
Long-term debt, net of discounts	1,377
Deferred income taxes, net	0
Pension and other post-retirement benefits	56
Other non-current liabilities	141
Total liabilities held for sale	1,822	$ 1,400
Allowance for doubtful accounts	21
Accumulated depreciation	$ 8,303