    <SEC-DOCUMENT>0001193125-23-241886-index.html : 20230926
    <SEC-HEADER>0001193125-23-241886.hdr.sgml : 20230926
    <ACCEPTANCE-DATETIME>20230926074430
    ACCESSION NUMBER:		0001193125-23-241886
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		24
    CONFORMED PERIOD OF REPORT:	20230926
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Other Events
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20230926
    DATE AS OF CHANGE:		20230926

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			REPLIGEN CORP
    		CENTRAL INDEX KEY:			0000730272
    		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
    		IRS NUMBER:				042729386
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-14656
    		FILM NUMBER:		231277168

    	BUSINESS ADDRESS:
    		STREET 1:		41 SEYON STREET
    		STREET 2:		BUILDING 1, SUITE 100
    		CITY:			WALTHAM
    		STATE:			MA
    		ZIP:			02453
    		BUSINESS PHONE:		7814499560

    	MAIL ADDRESS:
    		STREET 1:		41 SEYON STREET
    		STREET 2:		BUILDING 1, SUITE 100
    		CITY:			WALTHAM
    		STATE:			MA
    		ZIP:			02453
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>d561194d8k.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: d561194d8k.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>2
    <FILENAME>d561194dex991.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 2 - file: d561194dex991.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.2
    <SEQUENCE>3
    <FILENAME>d561194dex992.htm
    <DESCRIPTION>EX-99.2
    <TEXT>
    Document 3 - file: d561194dex992.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>4
    <FILENAME>rgen-20230926.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
    <TEXT>
    Document 4 - file: rgen-20230926.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>5
    <FILENAME>rgen-20230926_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE
    <TEXT>
    Document 5 - file: rgen-20230926_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>6
    <FILENAME>rgen-20230926_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE
    <TEXT>
    Document 6 - file: rgen-20230926_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>g561194ex99_2s1g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g561194ex99_2s1g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>g561194ex99_2s2g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: g561194ex99_2s2g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>g561194ex99_2s3g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: g561194ex99_2s3g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>g561194ex99_2s4g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g561194ex99_2s4g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g561194ex99_2s5g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g561194ex99_2s5g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>g561194ex99_2s6g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g561194ex99_2s6g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g561194ex99_2s7g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g561194ex99_2s7g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>g561194ex99_2s8g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g561194ex99_2s8g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>g561194ex99_2s9g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g561194ex99_2s9g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>g561194g0502055550953.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: g561194g0502055550953.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>17
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 17 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>18
    <FILENAME>d561194d8k_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 18 - file: d561194d8k_htm.html

    Document 18 - RAW XML: d561194d8k_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>19
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 19 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>20
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 20 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>21
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 21 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>22
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 22 - file: FilingSummary.html

    Document 22 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>25
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 25 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>26
    <FILENAME>0001193125-23-241886-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 26 - file: 0001193125-23-241886-xbrl.zip

    </DOCUMENT>
    </SEC-DOCUMENT>