<SEC-DOCUMENT>0000350894-18-000002-index.html : 20180201
<SEC-HEADER>0000350894-18-000002.hdr.sgml : 20180201
<ACCEPTANCE-DATETIME>20180201082059
ACCESSION NUMBER:		0000350894-18-000002
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20180131
ITEM INFORMATION:		Results of Operations and Financial Condition
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20180201
DATE AS OF CHANGE:		20180201

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:		18564733

	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>form8-k2118.htm
<DESCRIPTION>FORM 8-K
<TEXT>
Document 1 - file: form8-k2118.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>seic-earningsreleaseex9912.htm
<DESCRIPTION>PRESS RELEASE
<TEXT>
Document 2 - file: seic-earningsreleaseex9912.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>seiexhibit991logoa14.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: seiexhibit991logoa14.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>4
<FILENAME>seinwnaka02.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 4 - file: seinwnaka02.jpg

</DOCUMENT>
</SEC-DOCUMENT>