XML 50 R38.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Acquisition of the Predecessor - Narrative (Details) - Predecessor - USD ($) $ in Thousands |  | 3 Months Ended
--- | --- | ---
Nov. 05, 2015 | Mar. 31, 2017
Business Acquisition [Line Items] |  |
Cash paid | $ 50,830 |
Net cash paid in acquisition | 24,100 |
Cash acquired from acquisition | $ 26,700 |
Decrease in fair value of mineral interests |  | $ 3,500
Decrease to additional paid in capital |  | $ 3,500

X
- Definition Adjustments to Additional Paid in Capital, Purchase Accounting Adjustments + References No definition available. + Details
Name: | hcc_AdjustmentstoAdditionalPaidinCapitalPurchaseAccountingAdjustments
Namespace Prefix: | hcc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Mineral Interests + References No definition available. + Details
Name: | hcc_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentMineralInterests
Namespace Prefix: | hcc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow associated with the acquisition of business during the period (for example, cash that was held by the acquired business). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3179-108585 + Details
Name: | us-gaap_CashAcquiredFromAcquisition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 + Details
Name: | us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=hcc_ThePredecessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |