Income Taxes - Reconciliation of income taxes at the statutory rate to the provision for income taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Earnings before income taxes (“EBT”)	$ 255	$ 206	$ 519	$ 567
Income taxes at statutory rate	54	43	109	119
Effect of ESOP dividend paid deduction	0	(4)	(3)	(6)
Effect of stock-based compensation	0	(2)	(2)	(4)
Effect of tax exempt interest	(1)	(2)	(2)	(4)
Effect of dividends received deduction	0	0	(1)	(1)
Effect of nondeductible expenses	2	1	5	3
Effect of foreign operations	2	0	4	5
Effect of change in valuation allowance	0	1	0	(1)
Effect of other income	(2)	2	(3)	(1)
Provision for income taxes as shown on the Statement of Earnings	$ 55	$ 39	$ 107	$ 110
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income taxes at statutory rate as a percentage of EBT	21.00%	21.00%	21.00%	21.00%
Effect of ESOP dividend paid deduction as a percentage of EBT	0.00%	(2.00%)	(1.00%)	(1.00%)
Effect of stock-based compensation as a percentage of EBT	0.00%	(1.00%)	0.00%	(1.00%)
Effect of tax exempt interest as a percentage of EBT	0.00%	(1.00%)	0.00%	(1.00%)
Effect of dividends received deduction as a percentage of EBT	0.00%	0.00%	0.00%	0.00%
Effect of nondeductible expenses as a percentage of EBT	1.00%	0.00%	1.00%	1.00%
Effect of foreign operations as a percentage of EBT	1.00%	0.00%	1.00%	1.00%
Effect of change in valuation allowance as a percentage of EBT	0.00%	0.00%	0.00%	0.00%
Effect of other income tax reconciliation as a percentage of EBT	(1.00%)	2.00%	(1.00%)	(1.00%)
Provision for income taxes as shown on the Statement of Earnings as a percentage of EBT	22.00%	19.00%	21.00%	19.00%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deduction for dividend paid to employee stock ownership plan.

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The net result for the period of deducting operating expenses from operating revenues.

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