Document and Entity Information	Total
Prospectus:
Document Type	485BPOS
Document Period End Date	Dec. 31, 2020
Entity Registrant Name	HEARTLAND GROUP, INC
Entity Central Index Key	0000809586
Entity Inv Company Type	N-1A
Amendment Flag	false
Document Creation Date	Apr. 27, 2021
Document Effective Date	May 01, 2021
Prospectus Date	May 01, 2021
HEARTLAND MID CAP VALUE FUND \| Institutional Class
Prospectus:
Trading Symbol	HNMDX
HEARTLAND MID CAP VALUE FUND \| Investor Class
Prospectus:
Trading Symbol	HRMDX
HEARTLAND VALUE PLUS FUND \| Investor Class
Prospectus:
Trading Symbol	HRVIX
HEARTLAND VALUE PLUS FUND \| Institutional Class
Prospectus:
Trading Symbol	HNVIX
HEARTLAND VALUE FUND \| Investor Class
Prospectus:
Trading Symbol	HRTVX
HEARTLAND VALUE FUND \| Institutional Class
Prospectus:
Trading Symbol	HNTVX

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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