Escrow Deposit Disbursements Related To Business Acquisition, Period

No definition available.

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Namespace Prefix:	core_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Lessee, Capital Lease, Term Of Contract

+ References

No definition available.

+ Details

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Namespace Prefix:	core_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of indemnification assets (amounts to be reimbursed if and when certain assumed liabilities are paid) recognized at the acquisition date of a business combination.

+ References

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-Publisher FASB
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

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-Publisher FASB
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-Paragraph 2
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

+ References

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-Name Accounting Standards Codification
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+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=core_FarnerBockenCompanyMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Acquisitions - Narrative (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
Acquisitions - Narrative (Details) - USD ($) $ in Millions	Jul. 10, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jul. 31, 2019	Jul. 31, 2018
Business Acquisition [Line Items]
Acquisition related costs			$ 2.7
Obligations under finance leases			$ 26.2
Farner-Bocken Company
Business Acquisition [Line Items]
Total purchase consideration	$ 174.0
Consideration paid	169.0
Indemnity holdback	$ 5.0				$ 2.5	$ 2.5
Escrow Deposit Disbursements Related To Business Acquisition, Period	2 years
Capital lease, term				15 years
Obligations under finance leases		$ 15.8		$ 15.8
Net sales		703.4
Operating income		$ 9.4
Selling, General and Administrative Expenses \| Farner-Bocken Company
Business Acquisition [Line Items]
Acquisition related costs				$ 1.8