Cover
Jul. 01, 2021
Entity Information [Line Items]  
Document Type 8-K
Document Period End Date Jul. 01, 2021
Entity Registrant Name Heartland Financial USA, Inc.
Entity File Number 001-15393
Entity Incorporation, State or Country Code DE
Entity Tax Identification Number 42-1405748
Entity Address, Address Line One 1398 Central Avenue
Entity Address, City or Town Dubuque,
Entity Address, State or Province IA
Entity Address, Postal Zip Code 52001
City Area Code 563
Local Phone Number 589-2100
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Entity Emerging Growth Company false
Amendment Flag false
Entity Central Index Key 0000920112
Common Stock, par value $1.00 per share  
Entity Information [Line Items]  
Title of 12(b) Security Common Stock, par value $1.00 per share
Trading Symbol HTLF
Security Exchange Name NASDAQ
Depositary Shares (each representing 1/400th interest in a share of 7.00% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series E)  
Entity Information [Line Items]  
Title of 12(b) Security Depositary Shares (each representing 1/400th interest in a share of 7.00% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series E)
Trading Symbol HTLFP
Security Exchange Name NASDAQ