Pension and Savings Plans - Textual (Details)	3 Months Ended	12 Months Ended
	Apr. 01, 2017 numberOfPlan	Dec. 31, 2023	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of 401(k) plans | numberOfPlan	3
Paid discretionary contributions to defined contribution pension plans, company match			$ 20,100,000	$ 9,700,000	$ 9,600,000
Discretionary contributions to defined contribution pension plans, granted			9,200,000	0	0
Payment of prior performance contributions			4,000,000	0	0
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts			500,000,000
Australia
Defined Benefit Plan Disclosure [Line Items]
Paid discretionary contributions to defined contribution pension plans, company match			18,800,000	17,400,000	20,500,000
Discretionary contributions to defined contribution pension plans, granted			1,600,000	0	0
Payment of prior performance contributions			0	0	0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Payment for settlement					51,600,000
Settlement gain			0	0	2,700,000
Net actuarial (gain) loss			$ 20,600,000	$ 12,700,000	$ (25,600,000)
Expected long-term return on plan assets			3.20%	2.80%	3.60%
Accumulated benefit obligation			$ 580,900,000	$ 751,700,000
Defined benefit plan, assets			$ 583,300,000	772,400,000	$ 847,500,000
Percentage of company's qualified pension plans on a GAAP accounting basis			80.00%
Peabody Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, assets			$ 464,700,000	611,600,000
Plan with accumulated benefit obligation in excess of plan assets, accumulated benefit obligation			454,800,000	583,100,000
Western Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, assets			118,600,000	160,800,000
Plan with accumulated benefit obligation in excess of plan assets, accumulated benefit obligation			$ 126,100,000	$ 168,600,000
Fixed Income Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percentage			100.00%	100.00%
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Plan assets, target allocation, percentage			1.00%	1.00%
Scenario, Forecast | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets		4.90%
Scenario, Forecast | Western Plan
Defined Benefit Plan Disclosure [Line Items]
Expected long-term return on plan assets		4.65%