Income Taxes - Reconciliation of income taxes at the statutory rate to the provision for income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Earnings before income taxes (“EBT”)	$ 848	$ 1,108	$ 639
Income taxes at statutory rate	178	233	134
Effect of tax exempt interest	(12)	(14)	(13)
Effect of stock-based compensation	(4)	(8)	(8)
Effect of dividends received deduction	(3)	(4)	(4)
Effect of adjustments to prior year taxes	(1)	(3)	(8)
Effect of employee stock ownership plan dividend paid deduction	(2)	(2)	(3)
Effect of sale of subsidiaries	(72)	0	0
Effect of change in valuation allowance (excluding change in tax rate)	(117)	17	11
Effect of foreign operations	149	4	(2)
Effect of nondeductible expenses	5	8	7
Effect of other income tax reconciliation	6	8	8
Provision for income taxes as shown in the Statement of Earnings	$ 127	$ 239	$ 122
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income taxes at statutory rate as a percentage of EBT	21.00%	21.00%	21.00%
Effect of tax exempt interest as a percentage of EBT	(1.00%)	(1.00%)	(2.00%)
Effect of stock-based compensation as a percentage of EBT	0.00%	(1.00%)	(1.00%)
Effect of dividend received deduction as a percentage of EBT	0.00%	0.00%	(1.00%)
Effect of prior year income taxes as a percentage of EBT	0.00%	0.00%	(1.00%)
Effect of employee stock ownership plan dividend paid deduction as a percentage of EBT	0.00%	0.00%	(1.00%)
Effect sale of subsidiaries as a percentage of EBT	(8.00%)	0.00%	0.00%
Effect of change in valuation allowance (excluding change in tax rate) as a percentage of EBT	(14.00%)	2.00%	2.00%
Effect of foreign operations as a percentage of EBT	18.00%	0.00%	0.00%
Effect of nondeductible expenses as a percentage of EBT	1.00%	1.00%	1.00%
Effect of other income tax reconciliation as a percentage of EBT	(2.00%)	0.00%	1.00%
Provision for income taxes as shown in the Statement of Earnings as a percentage of EBT	15.00%	22.00%	19.00%