Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	0-10792
Entity Registrant Name	HORIZON BANCORP, INC.
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000706129
Current Fiscal Year End Date	--12-31
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-1562417
Entity Address, Address Line One	515 Franklin Street
Entity Address, City or Town	Michigan City
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46360
City Area Code	219
Local Phone Number	879-0211
Title of 12(b) Security	Common stock, no par value
Trading Symbol	HBNC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		43,880,562