Retirement Plans and Other Employee Benefits - Narrative (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) pensionPlan	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Minimum required outstanding par value to each issue of bonds	$ 300,000,000
Threshold amortization percentage of projected benefit obligation	10.00%
Threshold amortization, percentage of market-related value of plan assets	10.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 10,000,000	$ 4,000,000
Number of plans affected by interest credit ratings | pensionPlan	1
Funded status of the plans	$ 4,000,000	3,000,000
Qualified pension | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Estimated social security benefits age	65 years
Employer contributions	$ 6,000,000	0	$ 0
Funded status of the plans	37,000,000	41,000,000
Flexible Benefits Contribution
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	51,000,000	$ 37,000,000	$ 28,000,000
Nonqualified pension | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	5,000,000
Expected pension contribution	$ 5,000,000
Qualified pension/ postretirement benefits
Defined Benefit Plan Disclosure [Line Items]
Expected time horizon	30 years
Qualified pension/ postretirement benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Term used for assumption calculation	30 years
Savings Plan
Defined Benefit Plan Disclosure [Line Items]
Employer investment in qualified defined contribution plan	100.00%
Maximum percent of employee pre-tax contributions that may be matched by the Company (percent)	6.00%