<SEC-DOCUMENT>0000350894-22-000014-index.html : 20220404
<SEC-HEADER>0000350894-22-000014.hdr.sgml : 20220404
<ACCEPTANCE-DATETIME>20220404161106
ACCESSION NUMBER:		0000350894-22-000014
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		55
CONFORMED PERIOD OF REPORT:	20220331
ITEM INFORMATION:		Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers
ITEM INFORMATION:		Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20220404
DATE AS OF CHANGE:		20220404

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SEI INVESTMENTS CO
		CENTRAL INDEX KEY:			0000350894
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		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:		22802256

	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-20220331.htm
<DESCRIPTION>FORM 8-K
<TEXT>
Document 1 - file: seic-20220331.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>seic991hickeemploymentag.htm
<DESCRIPTION>EMPLOYMENT AGREEMENT
<TEXT>
Document 2 - file: seic991hickeemploymentag.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.2
<SEQUENCE>3
<FILENAME>seic992hickepressrelease.htm
<DESCRIPTION>PRESS RELEASE
<TEXT>
Document 3 - file: seic992hickepressrelease.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.3
<SEQUENCE>4
<FILENAME>seic993seiinvestmentscom.htm
<DESCRIPTION>AMENDED AND RESTATED BYLAWS
<TEXT>
Document 4 - file: seic993seiinvestmentscom.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-101.SCH
<SEQUENCE>5
<FILENAME>seic-20220331.xsd
<DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
<TEXT>
Document 5 - file: seic-20220331.xsd

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-101.LAB
<SEQUENCE>6
<FILENAME>seic-20220331_lab.xml
<DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT
<TEXT>
Document 6 - file: seic-20220331_lab.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-101.PRE
<SEQUENCE>7
<FILENAME>seic-20220331_pre.xml
<DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT
<TEXT>
Document 7 - file: seic-20220331_pre.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>seic-20220331_g1.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 8 - file: seic-20220331_g1.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>9
<FILENAME>seic991hickeemploymentag001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 9 - file: seic991hickeemploymentag001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>10
<FILENAME>seic991hickeemploymentag002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 10 - file: seic991hickeemploymentag002.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>11
<FILENAME>seic991hickeemploymentag003.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 11 - file: seic991hickeemploymentag003.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>12
<FILENAME>seic991hickeemploymentag004.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 12 - file: seic991hickeemploymentag004.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>13
<FILENAME>seic991hickeemploymentag005.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 13 - file: seic991hickeemploymentag005.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>14
<FILENAME>seic991hickeemploymentag006.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 14 - file: seic991hickeemploymentag006.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>15
<FILENAME>seic991hickeemploymentag007.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 15 - file: seic991hickeemploymentag007.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>16
<FILENAME>seic991hickeemploymentag008.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 16 - file: seic991hickeemploymentag008.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>17
<FILENAME>seic991hickeemploymentag009.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 17 - file: seic991hickeemploymentag009.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>18
<FILENAME>seic991hickeemploymentag010.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 18 - file: seic991hickeemploymentag010.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>19
<FILENAME>seic991hickeemploymentag011.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 19 - file: seic991hickeemploymentag011.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>20
<FILENAME>seic991hickeemploymentag012.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 20 - file: seic991hickeemploymentag012.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>21
<FILENAME>seic991hickeemploymentag013.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 21 - file: seic991hickeemploymentag013.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>22
<FILENAME>seic991hickeemploymentag014.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 22 - file: seic991hickeemploymentag014.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>23
<FILENAME>seic991hickeemploymentag015.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 23 - file: seic991hickeemploymentag015.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>24
<FILENAME>seic991hickeemploymentag016.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 24 - file: seic991hickeemploymentag016.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>25
<FILENAME>seic991hickeemploymentag017.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 25 - file: seic991hickeemploymentag017.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>26
<FILENAME>seic991hickeemploymentag018.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 26 - file: seic991hickeemploymentag018.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>27
<FILENAME>seic992hickepressrelease001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 27 - file: seic992hickepressrelease001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>28
<FILENAME>seic992hickepressrelease002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 28 - file: seic992hickepressrelease002.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>29
<FILENAME>seic993seiinvestmentscom001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 29 - file: seic993seiinvestmentscom001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>30
<FILENAME>seic993seiinvestmentscom002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 30 - file: seic993seiinvestmentscom002.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>31
<FILENAME>seic993seiinvestmentscom003.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 31 - file: seic993seiinvestmentscom003.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>32
<FILENAME>seic993seiinvestmentscom004.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 32 - file: seic993seiinvestmentscom004.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>33
<FILENAME>seic993seiinvestmentscom005.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 33 - file: seic993seiinvestmentscom005.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>34
<FILENAME>seic993seiinvestmentscom006.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 34 - file: seic993seiinvestmentscom006.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>35
<FILENAME>seic993seiinvestmentscom007.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 35 - file: seic993seiinvestmentscom007.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>36
<FILENAME>seic993seiinvestmentscom008.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 36 - file: seic993seiinvestmentscom008.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>37
<FILENAME>seic993seiinvestmentscom009.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 37 - file: seic993seiinvestmentscom009.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>38
<FILENAME>seic993seiinvestmentscom010.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 38 - file: seic993seiinvestmentscom010.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>39
<FILENAME>seic993seiinvestmentscom011.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 39 - file: seic993seiinvestmentscom011.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>40
<FILENAME>seic993seiinvestmentscom012.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 40 - file: seic993seiinvestmentscom012.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>41
<FILENAME>seic993seiinvestmentscom013.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 41 - file: seic993seiinvestmentscom013.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>42
<FILENAME>seic993seiinvestmentscom014.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 42 - file: seic993seiinvestmentscom014.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>43
<FILENAME>seic993seiinvestmentscom015.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 43 - file: seic993seiinvestmentscom015.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>44
<FILENAME>seic993seiinvestmentscom016.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 44 - file: seic993seiinvestmentscom016.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>45
<FILENAME>seic993seiinvestmentscom017.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 45 - file: seic993seiinvestmentscom017.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>46
<FILENAME>seic993seiinvestmentscom018.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 46 - file: seic993seiinvestmentscom018.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>47
<FILENAME>seic993seiinvestmentscom019.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 47 - file: seic993seiinvestmentscom019.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>48
<FILENAME>R1.htm
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 48 - file: R1.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>49
<FILENAME>seic-20220331_htm.xml
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 49 - file: seic-20220331_htm.html

Document 49 - RAW XML: seic-20220331_htm.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>EXCEL
<SEQUENCE>50
<FILENAME>Financial_Report.xlsx
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 50 - file: Financial_Report.xlsx

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>51
<FILENAME>Show.js
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 51 - file: Show.js

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>52
<FILENAME>report.css
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 52 - file: report.css

</DOCUMENT>
<DOCUMENT>
<TYPE>XML
<SEQUENCE>53
<FILENAME>FilingSummary.xml
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 53 - file: FilingSummary.html

Document 53 - RAW XML: FilingSummary.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>JSON
<SEQUENCE>55
<FILENAME>MetaLinks.json
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 55 - file: MetaLinks.json

</DOCUMENT>
<DOCUMENT>
<TYPE>ZIP
<SEQUENCE>56
<FILENAME>0000350894-22-000014-xbrl.zip
<DESCRIPTION>IDEA: XBRL DOCUMENT
<TEXT>
Document 56 - file: 0000350894-22-000014-xbrl.zip

</DOCUMENT>
</SEC-DOCUMENT>