Supplemental Guarantor/Non-Guarantor Financial Information Supplemental DND financial information details 5 (Details) - USD ($) $ in Millions	Dec. 31, 2016	Apr. 12, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and cash equivalents	$ 872.3	$ 652.1	$ 261.3	$ 298.0	$ 444.0
Restricted Cash and Investments, Current	54.3		0.0
Accounts receivable, net	473.0		228.8
Receivables from affiliates, net	0.0		0.0
Inventory, Net	203.7		307.8
Assets From Coal Trading Activities, Net	0.7		23.5
Deferred Tax Assets, Net of Valuation Allowance, Current	0.0		53.5
Other current assets	486.6		447.6
Assets, Current	2,090.6		1,322.5
Property, Plant and Equipment, Net	8,776.7		9,258.5	10,577.3
Deferred income taxes	0.0		2.2
Other Assets, Noncurrent	910.4		363.7
Notes Receivable, Related Parties	0.0		0.0
Total assets	11,777.7		10,946.9	13,191.1
Long-term Debt and Capital Lease Obligations, Current	20.2		5,874.9
Payables to affiliates, net	0.0		0.0
Taxes Payable, Current	6.2
Liabilities from coal trading activities, net	1.2		15.6
Accounts Payable and Other Accrued Liabilities, Current	984.2		1,442.5
Liabilities, Current	1,011.8		7,336.8
Deferred Tax Liabilities, Net, Noncurrent	17.6		69.1
Notes Payable, Related Parties, Noncurrent	0.0		0.0
Other noncurrent liabilities	1,970.3		2,256.2
Total liabilities not subject to compromise	2,999.7		10,028.4
Liabilities Subject to Compromise	8,440.2		0.0
Liabilities	11,439.9		10,028.4
Peabody Energy Corporation's stockholders' equity	330.2		916.9
Stockholders' Equity Attributable to Noncontrolling Interest	7.6		1.6
Total stockholders' equity	337.8		918.5	2,726.5	3,947.9
Liabilities and Equity	11,777.7		10,946.9
Noncontrolling Interest [Member]
Total stockholders' equity	7.6		$ 1.6	$ 1.7	$ 39.2
Debtor Non-Debtor Eliminations [Member]
Cash and cash equivalents	0.0
Restricted Cash and Investments, Current	0.0
Accounts receivable, net	0.0
Receivables from affiliates, net	(226.9)
Inventory, Net	0.0
Assets From Coal Trading Activities, Net	(0.2)
Deferred Tax Assets, Net of Valuation Allowance, Current	0.0
Other current assets	(1.6)
Assets, Current	(228.7)
Property, Plant and Equipment, Net	0.0
Deferred income taxes	0.0
Other Assets, Noncurrent	(3,968.5)
Notes Receivable, Related Parties	(1,036.3)
Total assets	(5,233.5)
Long-term Debt and Capital Lease Obligations, Current	0.0
Payables to affiliates, net	(226.9)
Taxes Payable, Current	(1.6)
Liabilities from coal trading activities, net	(0.2)
Accounts Payable and Other Accrued Liabilities, Current	0.0
Liabilities, Current	(228.7)
Notes Payable, Related Parties, Noncurrent	(1,036.3)
Other noncurrent liabilities	0.0
Total liabilities not subject to compromise	(1,265.0)
Liabilities Subject to Compromise	0.0
Liabilities	(1,265.0)
Peabody Energy Corporation's stockholders' equity	(3,968.5)
Stockholders' Equity Attributable to Noncontrolling Interest	0.0
Total stockholders' equity	(3,968.5)
Liabilities and Equity	$ (5,233.5)