Share-Based Compensation - Performance Share Units (Details) - PSUs - Suncoke LTPEP	9 Months Ended
Sep. 30, 2020 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares) \| shares	228,248
Weighted Average Per Share Grant Date Fair Value (in dollars per share) \| $ / shares	$ 6.70
Pre-tax return of capital for Coke and Coal Logistics businesses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of award allocation	50.00%
Measurement period	3 years
TSR \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement results payout percentage	75.00%
TSR \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement results payout percentage	125.00%

Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Measurement Period

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Measurement Results Payout Percentage

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Share-based Compensation Arrangement by Share-based Payment Award, Percent of Award Allocation

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Gross number of share options (or share units) granted during the period.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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