Supplemental Condensed Consolidating Financial Information (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Assets
Cash and cash equivalents	$ 178.2	$ 233.6	$ 307.1	$ 239.2
Receivables	81.5	91.5
Inventories	124.8	135.3
Income tax receivable	5.6	6.6
Deferred income taxes	12.6	12.6
Other current assets	7.5	2.3
Advances to affiliates	0	0
Advances to affiliate	0	0
Total current assets	410.2	481.9
Notes receivable from affiliate	0	0
Investment in Brazilian cokemaking operations	41.0	41.0
Equity method investment in VISA SunCoke Limited	56.8	56.8
Properties, plants and equipment, net	1,553.2	1,544.1
Lease and mineral rights, net	52.7	52.8
Goodwill	25.1
Goodwill and other intangible assets, net	25.1	25.4
Deferred charges and other assets	44.5	41.9
Investment in subsidiaries	0	0
Total assets	2,183.5	2,243.9
Liabilities and Equity
Advances from affiliate	0	0
Accounts payable	136.3	154.3
Current portion of long term debt	41.0	41.0
Accrued liabilities	46.8	69.5
Interest payable	7.8	18.2
Interest payable to affiliate	0	0
Income taxes payable	0	0
Total current liabilities	231.9	283.0
Long-term debt	647.9	648.1
Payable to affiliate	0	0
Accrual for black lung benefits	32.4	32.4
Retirement benefit liabilities	35.0	34.8
Deferred income taxes	373.1	376.6
Asset retirement obligations	18.2	17.9
Other deferred credits and liabilities	20.0	18.8
Total liabilities	1,358.5	1,411.6
Equity
Preferred stock, $0.01 par value. Authorized 50,000,000 shares; no issued and outstanding shares at March 31, 2014 and December 31, 2013	0	0
Common stock, $0.01 par value. Authorized 300,000,000 shares; issued and outstanding 69,762,824 and 69,636,785 shares at March 31, 2014 and December 31, 2013, respectively	0.7	0.7
Treasury stock,1,255,355 shares at March 31, 2014 and at December 31, 2013	(19.9)	(19.9)
Additional paid-in capital	449.6	446.9
Accumulated other comprehensive loss	(13.9)	(14.1)	(8.3)	(7.9)
Retained earnings	136.0	143.8
Total SunCoke Energy, Inc. stockholders’ equity	552.5	557.4
Noncontrolling interests	272.5	274.9
Total equity	825.0	832.3	810.8	574.9
Total liabilities and equity	2,183.5	2,243.9
Issuer
Assets
Cash and cash equivalents	0	0	0	0
Receivables	0.1	0
Inventories	0	0
Income tax receivable	35.3	39.9
Deferred income taxes	9.2	9.4
Other current assets	0	0
Advances to affiliates	34.1	48.2
Advances to affiliate	0	0
Total current assets	78.7	97.5
Notes receivable from affiliate	0	0
Investment in Brazilian cokemaking operations	0	0
Equity method investment in VISA SunCoke Limited	0	0
Properties, plants and equipment, net	0	0
Lease and mineral rights, net	0	0
Goodwill	0
Goodwill and other intangible assets, net		0
Deferred charges and other assets	11.2	11.7
Investment in subsidiaries	970.1	963.3
Total assets	1,060.0	1,072.5
Liabilities and Equity
Advances from affiliate	0	0
Accounts payable	0	0
Current portion of long term debt	1.0	1.0
Accrued liabilities	0.6	0.5
Interest payable	6.0	13.6
Interest payable to affiliate	0	0
Income taxes payable	0	0
Total current liabilities	7.6	15.1
Long-term debt	498.2	498.4
Payable to affiliate	0	0
Accrual for black lung benefits	0	0
Retirement benefit liabilities	0	0
Deferred income taxes	0	0
Asset retirement obligations	0	0
Other deferred credits and liabilities	1.7	1.6
Total liabilities	507.5	515.1
Equity
Preferred stock, $0.01 par value. Authorized 50,000,000 shares; no issued and outstanding shares at March 31, 2014 and December 31, 2013	0	0
Common stock, $0.01 par value. Authorized 300,000,000 shares; issued and outstanding 69,762,824 and 69,636,785 shares at March 31, 2014 and December 31, 2013, respectively	0.7	0.7
Treasury stock,1,255,355 shares at March 31, 2014 and at December 31, 2013	(19.9)	(19.9)
Additional paid-in capital	449.6	446.9
Accumulated other comprehensive loss	(13.9)	(14.1)
Retained earnings	136.0	143.8
Total SunCoke Energy, Inc. stockholders’ equity	552.5	557.4
Noncontrolling interests	0	0
Total equity	552.5	557.4
Total liabilities and equity	1,060.0	1,072.5
Guarantor Subsidiaries
Assets
Cash and cash equivalents	154.8	184.7	194.9	206.9
Receivables	27.5	53.4
Inventories	43.1	44.1
Income tax receivable	0	0
Deferred income taxes	11.8	11.8
Other current assets	5.1	1.3
Advances to affiliates	72.1	33.6
Advances to affiliate	1.8	7.3
Total current assets	316.2	336.2
Notes receivable from affiliate	89.0	89.0
Investment in Brazilian cokemaking operations	0	0
Equity method investment in VISA SunCoke Limited	0	0
Properties, plants and equipment, net	495.4	500.9
Lease and mineral rights, net	52.7	52.8
Goodwill	9.4
Goodwill and other intangible assets, net		9.4
Deferred charges and other assets	22.8	20.5
Investment in subsidiaries	789.2	723.8
Total assets	1,774.7	1,732.6
Liabilities and Equity
Advances from affiliate	34.1	48.2
Accounts payable	44.0	48.8
Current portion of long term debt	0	0
Accrued liabilities	30.7	52.6
Interest payable	0	0
Interest payable to affiliate	0	0
Income taxes payable	43.5	46.7
Total current liabilities	152.3	196.3
Long-term debt	0	0
Payable to affiliate	300.0	300.0
Accrual for black lung benefits	32.4	32.4
Retirement benefit liabilities	35.0	34.8
Deferred income taxes	379.9	383.9
Asset retirement obligations	15.7	15.5
Other deferred credits and liabilities	17.6	16.6
Total liabilities	932.9	979.5
Equity
Preferred stock, $0.01 par value. Authorized 50,000,000 shares; no issued and outstanding shares at March 31, 2014 and December 31, 2013	0	0
Common stock, $0.01 par value. Authorized 300,000,000 shares; issued and outstanding 69,762,824 and 69,636,785 shares at March 31, 2014 and December 31, 2013, respectively	0	0
Treasury stock,1,255,355 shares at March 31, 2014 and at December 31, 2013	0	0
Additional paid-in capital	430.9	354.2
Accumulated other comprehensive loss	(3.3)	(2.7)
Retained earnings	414.2	401.6
Total SunCoke Energy, Inc. stockholders’ equity	841.8	753.1
Noncontrolling interests	0	0
Total equity	841.8	753.1
Total liabilities and equity	1,774.7	1,732.6
Non- Guarantor Subsidiaries
Assets
Cash and cash equivalents	23.4	48.9	112.2	32.3
Receivables	53.9	38.1
Inventories	81.7	91.2
Income tax receivable	13.8	13.4
Deferred income taxes	0.8	0.8
Other current assets	2.4	1.0
Advances to affiliates	0	0
Advances to affiliate	0	0
Total current assets	176.0	193.4
Notes receivable from affiliate	300.0	300.0
Investment in Brazilian cokemaking operations	41.0	41.0
Equity method investment in VISA SunCoke Limited	56.8	56.8
Properties, plants and equipment, net	1,057.8	1,043.2
Lease and mineral rights, net	0	0
Goodwill	15.7
Goodwill and other intangible assets, net		16.0
Deferred charges and other assets	10.5	9.7
Investment in subsidiaries	0	0
Total assets	1,657.8	1,660.1
Liabilities and Equity
Advances from affiliate	72.1	33.6
Accounts payable	92.3	105.5
Current portion of long term debt	40.0	40.0
Accrued liabilities	15.5	16.4
Interest payable	1.8	4.6
Interest payable to affiliate	1.8	7.3
Income taxes payable	0	0
Total current liabilities	223.5	207.4
Long-term debt	149.7	149.7
Payable to affiliate	89.0	89.0
Accrual for black lung benefits	0	0
Retirement benefit liabilities	0	0
Deferred income taxes	2.4	2.1
Asset retirement obligations	2.5	2.4
Other deferred credits and liabilities	0.7	0.6
Total liabilities	467.8	451.2
Equity
Preferred stock, $0.01 par value. Authorized 50,000,000 shares; no issued and outstanding shares at March 31, 2014 and December 31, 2013	0	0
Common stock, $0.01 par value. Authorized 300,000,000 shares; issued and outstanding 69,762,824 and 69,636,785 shares at March 31, 2014 and December 31, 2013, respectively	0	0
Treasury stock,1,255,355 shares at March 31, 2014 and at December 31, 2013	0	0
Additional paid-in capital	724.9	745.6
Accumulated other comprehensive loss	(10.6)	(11.4)
Retained earnings	203.2	199.8
Total SunCoke Energy, Inc. stockholders’ equity	917.5	934.0
Noncontrolling interests	272.5	274.9
Total equity	1,190.0	1,208.9
Total liabilities and equity	1,657.8	1,660.1
Combining and Consolidating Adjustments
Assets
Cash and cash equivalents	0	0	0	0
Receivables	0	0
Inventories	0	0
Income tax receivable	(43.5)	(46.7)
Deferred income taxes	(9.2)	(9.4)
Other current assets	0	0
Advances to affiliates	(106.2)	(81.8)
Advances to affiliate	(1.8)	(7.3)
Total current assets	(160.7)	(145.2)
Notes receivable from affiliate	(389.0)	(389.0)
Investment in Brazilian cokemaking operations	0
Equity method investment in VISA SunCoke Limited	0	0
Properties, plants and equipment, net	0	0
Lease and mineral rights, net	0	0
Goodwill	0
Goodwill and other intangible assets, net		0
Deferred charges and other assets	0	0
Investment in subsidiaries	(1,759.3)	(1,687.1)
Total assets	(2,309.0)	(2,221.3)
Liabilities and Equity
Advances from affiliate	(106.2)	(81.8)
Accounts payable	0	0
Current portion of long term debt	0	0
Accrued liabilities	0	0
Interest payable	0	0
Interest payable to affiliate	(1.8)	(7.3)
Income taxes payable	(43.5)	(46.7)
Total current liabilities	(151.5)	(135.8)
Long-term debt	0	0
Payable to affiliate	(389.0)	(389.0)
Accrual for black lung benefits	0	0
Retirement benefit liabilities	0	0
Deferred income taxes	(9.2)	(9.4)
Asset retirement obligations	0	0
Other deferred credits and liabilities	0	0
Total liabilities	(549.7)	(534.2)
Equity
Preferred stock, $0.01 par value. Authorized 50,000,000 shares; no issued and outstanding shares at March 31, 2014 and December 31, 2013	0	0
Common stock, $0.01 par value. Authorized 300,000,000 shares; issued and outstanding 69,762,824 and 69,636,785 shares at March 31, 2014 and December 31, 2013, respectively	0	0
Treasury stock,1,255,355 shares at March 31, 2014 and at December 31, 2013	0	0
Additional paid-in capital	(1,155.8)	(1,099.8)
Accumulated other comprehensive loss	13.9	14.1
Retained earnings	(617.4)	(601.4)
Total SunCoke Energy, Inc. stockholders’ equity	(1,759.3)	(1,687.1)
Noncontrolling interests	0	0
Total equity	(1,759.3)	(1,687.1)
Total liabilities and equity	$ (2,309.0)	$ (2,221.3)