Cover - shares	9 Months Ended
	Sep. 30, 2019	Nov. 04, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-15393
Entity Registrant Name	HEARTLAND FINANCIAL USA, INC.
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
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, par value $1.00 per share
Trading Symbol	HTLF
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		36,698,445
Entity Central Index Key	0000920112
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false