    <SEC-DOCUMENT>0001193125-23-200644-index.html : 20230801
    <SEC-HEADER>0001193125-23-200644.hdr.sgml : 20230801
    <ACCEPTANCE-DATETIME>20230801170806
    ACCESSION NUMBER:		0001193125-23-200644
    CONFORMED SUBMISSION TYPE:	N-2/A
    PUBLIC DOCUMENT COUNT:		22
    FILED AS OF DATE:		20230801
    DATE AS OF CHANGE:		20230801

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			NUVEEN CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		CENTRAL INDEX KEY:			0000885732
    		IRS NUMBER:				363828111
    		STATE OF INCORPORATION:			MA

    	FILING VALUES:
    		FORM TYPE:		N-2/A
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-06623
    		FILM NUMBER:		231132708

    	BUSINESS ADDRESS:
    		STREET 1:		333 W WACKER DR
    		CITY:			CHICAGO
    		STATE:			IL
    		ZIP:			60606
    		BUSINESS PHONE:		3129178200

    	MAIL ADDRESS:
    		STREET 1:		333 W WACKER DRIVE
    		CITY:			CHICAGO
    		STATE:			IL
    		ZIP:			60606

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NUVEEN INSURED CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		DATE OF NAME CHANGE:	19920929

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NUVEEN CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		DATE OF NAME CHANGE:	19600201

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			NUVEEN CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		CENTRAL INDEX KEY:			0000885732
    		IRS NUMBER:				363828111
    		STATE OF INCORPORATION:			MA

    	FILING VALUES:
    		FORM TYPE:		N-2/A
    		SEC ACT:		1933 Act
    		SEC FILE NUMBER:	333-271871
    		FILM NUMBER:		231132707

    	BUSINESS ADDRESS:
    		STREET 1:		333 W WACKER DR
    		CITY:			CHICAGO
    		STATE:			IL
    		ZIP:			60606
    		BUSINESS PHONE:		3129178200

    	MAIL ADDRESS:
    		STREET 1:		333 W WACKER DRIVE
    		CITY:			CHICAGO
    		STATE:			IL
    		ZIP:			60606

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NUVEEN INSURED CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		DATE OF NAME CHANGE:	19920929

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	NUVEEN CALIFORNIA SELECT TAX FREE INCOME PORTFOLIO
    		DATE OF NAME CHANGE:	19600201
    <IS-FILER-A-NEW-REGISTRANT>N
    <IS-FILER-A-WELL-KNOWN-SEASONED-ISSUER>N
    <FILED-PURSUANT-TO-GENERAL-INSTRUCTION-A2>Y
    <IS-FUND-24F2-ELIGIBLE>N
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-2/A
    <SEQUENCE>1
    <FILENAME>d422297dn2a.htm
    <DESCRIPTION>NUVEEN CALIFORNIA SELECT TAX-FREE INCOME PORTFOLIO
    <TEXT>
    Document 1 - file: d422297dn2a.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.H1
    <SEQUENCE>2
    <FILENAME>d422297dex99h1.htm
    <DESCRIPTION>DISTRIBUTION AGREEMENT, DATED JULY 28, 2023, RELATING TO AT-THE-MARKET OFFERINGS
    <TEXT>
    Document 2 - file: d422297dex99h1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.H2
    <SEQUENCE>3
    <FILENAME>d422297dex99h2.htm
    <DESCRIPTION>DEALER AGREEMENT, DATED JULY 28, 2023
    <TEXT>
    Document 3 - file: d422297dex99h2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.L1
    <SEQUENCE>4
    <FILENAME>d422297dex99l1.htm
    <DESCRIPTION>CONSENT OF MORGAN, LEWIS & BOCKIUS LLP
    <TEXT>
    Document 4 - file: d422297dex99l1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.L2
    <SEQUENCE>5
    <FILENAME>d422297dex99l2.htm
    <DESCRIPTION>OPINION AND CONSENT OF COUNSEL, MORGAN, LEWIS & BOCKIUS LLP
    <TEXT>
    Document 5 - file: d422297dex99l2.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.N
    <SEQUENCE>6
    <FILENAME>d422297dex99n.htm
    <DESCRIPTION>CONSENT OF KPMG LLP
    <TEXT>
    Document 6 - file: d422297dex99n.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-FILING FEES
    <SEQUENCE>7
    <FILENAME>d422297dexfilingfees.htm
    <DESCRIPTION>CALCULATION OF FILING FEE TABLES
    <TEXT>
    Document 7 - file: d422297dexfilingfees.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>9
    <FILENAME>ncstfip-20230731.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA
    <TEXT>
    Document 9 - file: ncstfip-20230731.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>g422297dsp63.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g422297dsp63.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g422297dsp64.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g422297dsp64.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>g422297dsp67.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g422297dsp67.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g422297g0509064555174.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g422297g0509064555174.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>g422297g0509064555283.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g422297g0509064555283.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>g422297g58b43.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g422297g58b43.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>g422297g62s26.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: g422297g62s26.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>d422297dn2a_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 18 - file: d422297dn2a_htm.html

    Document 18 - RAW XML: d422297dn2a_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>19
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 19 - file: Show.js

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

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>21
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 21 - file: FilingSummary.html

    Document 21 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>24
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 24 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>25
    <FILENAME>0001193125-23-200644-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 25 - file: 0001193125-23-200644-xbrl.zip

    </DOCUMENT>
    </SEC-DOCUMENT>