    <SEC-DOCUMENT>0000350894-25-000032-index.html : 20250227
    <SEC-HEADER>0000350894-25-000032.hdr.sgml : 20250227
    <ACCEPTANCE-DATETIME>20250227101633
    ACCESSION NUMBER:		0000350894-25-000032
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		18
    CONFORMED PERIOD OF REPORT:	20250227
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20250227
    DATE AS OF CHANGE:		20250227

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			SEI INVESTMENTS CO
    		CENTRAL INDEX KEY:			0000350894
    		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
    		ORGANIZATION NAME:           	09 Crypto Assets
    		IRS NUMBER:				231707341
    		STATE OF INCORPORATION:			PA
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-10200
    		FILM NUMBER:		25674056

    	BUSINESS ADDRESS:
    		STREET 1:		1 FREEDOM VALLEY DRIVE
    		CITY:			OAKS
    		STATE:			PA
    		ZIP:			19456-1100
    		BUSINESS PHONE:		6106761000

    	MAIL ADDRESS:
    		STREET 1:		1 FREEDOM VALLEY DRIVE
    		CITY:			OAKS
    		STATE:			PA
    		ZIP:			19456-1100

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	SEI INVESTMENT CO
    		DATE OF NAME CHANGE:	20040806

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	SEI CORP
    		DATE OF NAME CHANGE:	19920703
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>seic-20250227.htm
    <DESCRIPTION>FORM 8-K
    <TEXT>
    Document 1 - file: seic-20250227.htm

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

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>3
    <FILENAME>seic-20250227.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
    Document 3 - file: seic-20250227.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>4
    <FILENAME>seic-20250227_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT
    <TEXT>
    Document 4 - file: seic-20250227_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>5
    <FILENAME>seic-20250227_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT
    <TEXT>
    Document 5 - file: seic-20250227_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>pressrelease_projectbeek001.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: pressrelease_projectbeek001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>pressrelease_projectbeek002.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: pressrelease_projectbeek002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>pressrelease_projectbeek003.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: pressrelease_projectbeek003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>seic-20250227_g1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: seic-20250227_g1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>11
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 11 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>12
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 12 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>13
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 13 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>14
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 14 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>16
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 16 - file: FilingSummary.html

    Document 16 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>18
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 18 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>19
    <FILENAME>0000350894-25-000032-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 19 - file: 0000350894-25-000032-xbrl.zip

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>20
    <FILENAME>seic-20250227_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 20 - file: seic-20250227_htm.html

    Document 20 - RAW XML: seic-20250227_htm.xml

    </DOCUMENT>
    </SEC-DOCUMENT>