    <SEC-DOCUMENT>0001193125-24-060505-index.html : 20240306
    <SEC-HEADER>0001193125-24-060505.hdr.sgml : 20240306
    <ACCEPTANCE-DATETIME>20240306135348
    ACCESSION NUMBER:		0001193125-24-060505
    CONFORMED SUBMISSION TYPE:	N-CSR
    PUBLIC DOCUMENT COUNT:		31
    CONFORMED PERIOD OF REPORT:	20231231
    FILED AS OF DATE:		20240306
    DATE AS OF CHANGE:		20240306
    EFFECTIVENESS DATE:		20240306

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			BLACKROCK CORE BOND TRUST
    		CENTRAL INDEX KEY:			0001160864
    		ORGANIZATION NAME:
    		IRS NUMBER:				522346891
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1031

    	FILING VALUES:
    		FORM TYPE:		N-CSR
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-10543
    		FILM NUMBER:		24725262

    	BUSINESS ADDRESS:
    		STREET 1:		100 BELLEVUE PARKWAY
    		STREET 2:		MUTUAL FUND DEPARTMENT
    		CITY:			WILMINGTON
    		STATE:			DE
    		ZIP:			19809
    		BUSINESS PHONE:		888-825-2257

    	MAIL ADDRESS:
    		STREET 1:		100 BELLEVUE PARKWAY
    		STREET 2:		MUTUAL FUND DEPARTMENT
    		CITY:			WILMINGTON
    		STATE:			DE
    		ZIP:			19809
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-CSR
    <SEQUENCE>1
    <FILENAME>d632386dncsr.htm
    <DESCRIPTION>BLACKROCK CORE BOND TRUST
    <TEXT>
    Document 1 - file: d632386dncsr.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>d632386dex99cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 302
    <TEXT>
    Document 2 - file: d632386dex99cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906CERT
    <SEQUENCE>3
    <FILENAME>d632386dex99906cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 906
    <TEXT>
    Document 3 - file: d632386dex99906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CONSENT
    <SEQUENCE>4
    <FILENAME>d632386dex99consent.htm
    <DESCRIPTION>CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
    <TEXT>
    Document 4 - file: d632386dex99consent.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.PROXYPOL
    <SEQUENCE>5
    <FILENAME>d632386dex99proxypol.htm
    <DESCRIPTION>PROXY VOTING POLICY AND PROCEDURES
    <TEXT>
    Document 5 - file: d632386dex99proxypol.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.GLOBALCORPGOV
    <SEQUENCE>6
    <FILENAME>d632386dex99globalcorpgov.htm
    <DESCRIPTION>GLOBAL CORPORATE GOVERNANCE & ENGAGEMENT PRINCIPLES
    <TEXT>
    Document 6 - file: d632386dex99globalcorpgov.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.USCORPGOV
    <SEQUENCE>7
    <FILENAME>d632386dex99uscorpgov.htm
    <DESCRIPTION>CORPORATE GOVERNANCE AND PROXY VOTING GUIDELINES FOR U.S. SECURITIES
    <TEXT>
    Document 7 - file: d632386dex99uscorpgov.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.SECTION19
    <SEQUENCE>8
    <FILENAME>d632386dex99section19.htm
    <DESCRIPTION>SECTION 19 NOTICES
    <TEXT>
    Document 8 - file: d632386dex99section19.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>9
    <FILENAME>bcbt-20240305.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
    <TEXT>
    Document 9 - file: bcbt-20240305.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>g179418g16g16.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g179418g16g16.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g179418g37g37.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g179418g37g37.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>g179418sp15a.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g179418sp15a.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g179418sp15aa.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g179418sp15aa.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>g632386g42l24.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g632386g42l24.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>g632386g43e33.gif
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g632386g43e33.gif

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>g632386g81k01.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: g632386g81k01.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>g632386g81k02.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: g632386g81k02.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>g632386g81k03.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: g632386g81k03.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>g632386g81k04.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: g632386g81k04.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>g632386photo_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: g632386photo_01mips.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>g632386sig_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: g632386sig_01mips.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>22
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 22 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>24
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 24 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>25
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 25 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>26
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 26 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>28
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 28 - file: FilingSummary.html

    Document 28 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>31
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 31 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>32
    <FILENAME>0001193125-24-060505-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 32 - file: 0001193125-24-060505-xbrl.zip

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>33
    <FILENAME>d632386dncsr_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 33 - file: d632386dncsr_htm.html

    Document 33 - RAW XML: d632386dncsr_htm.xml

    </DOCUMENT>
    </SEC-DOCUMENT>