Document and Entity Information
Document and Entity Information | Oct. 21, 2020 |
Document and Entity Information [Abstract] | |
Document Type | 8-K |
Document Period End Date | Oct. 21, 2020 |
Entity Registrant Name | OLD SECOND BANCORP INC |
Entity Incorporation, State or Country Code | DE |
Entity File Number | 000-10537 |
Entity Tax Identification Number | 36-3143493 |
Entity Address, Address Line One | 37 South River Street |
Entity Address, City or Town | Aurora |
Entity Address, State or Province | IL |
Entity Address, Postal Zip Code | 60507 |
City Area Code | 630 |
Local Phone Number | 892-0202 |
Written Communications | false |
Soliciting Material | false |
Pre-commencement Tender Offer | false |
Pre-commencement Issuer Tender Offer | false |
Title of 12(b) Security | Common Stock |
Trading Symbol | OSBC |
Security Exchange Name | NASDAQ |
Entity Emerging Growth Company | false |
Entity Central Index Key | 0000357173 |
Amendment Flag | false |