Income Taxes - Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Employee and retiree benefit plans	$ 304
Employee and retiree benefit plans		$ 477
Other insurance and contractholder liabilities	263
Other insurance and contractholder liabilities		278
Loss carryforwards	278
Loss carryforwards		177
Other accrued liabilities	412
Other accrued liabilities		358
Other	245
Other		209
Deferred tax assets before valuation allowance	1,503
Deferred tax assets before valuation allowance		1,499
Valuation allowance for deferred tax assets	(246)
Valuation allowance for deferred tax assets		(207)
Deferred tax assets, net of valuation allowance	1,257
Deferred tax assets, net of valuation allowance		1,292
Deferred tax liabilities
Depreciation and amortization	698
Depreciation and amortization		660
Acquisition-related basis differences	8,726
Acquisition-related basis differences		8,989
Policy acquisition expenses	312
Policy acquisition expenses		289
Unrealized appreciation on investments and foreign currency translation	104
Unrealized appreciation on investments and foreign currency translation		171
Other	212
Other		122
Total deferred tax liabilities	10,052
Total deferred tax liabilities		10,231
Net deferred income tax (liabilities)	(8,795)
Net deferred income tax (liabilities) assets classified as Liabilities of businesses held for sale	(449)
Net deferred income tax (liabilities) assets per Consolidated Balance Sheets	$ (8,346)	$ (8,939)