| Cover | Nov. 09, 2020 | Aug. 10, 2020 |
| Document Type | 8-K | |
| Document Period End Date | Nov. 9, 2020 | |
| Entity Registrant Name | Infrastructure & Energy Alternatives, Inc. | |
| Entity File Number | 001-37796 | |
| Entity Incorporation, State or Country Code | DE | |
| Entity Tax Identification Number | 47-4787177 | |
| Entity Address, Address Line One | 6325 Digital Way | |
| Entity Address, Address Line Two | Suite 460 | |
| Entity Address, City or Town | Indianapolis | |
| Entity Address, State or Province | IN | |
| Entity Address, Postal Zip Code | 46278 | |
| City Area Code | 765 | |
| Local Phone Number | 828-2580 | |
| Written Communications | false | |
| Soliciting Material | false | |
| Pre-commencement Tender Offer | false | |
| Pre-commencement Issuer Tender Offer | false | |
| Entity Emerging Growth Company | false | |
| Document Fiscal Year Focus | 2020 | |
| Document Fiscal Period Focus | Q3 | |
| Amendment Flag | false | |
| Entity Central Index Key | 0001652362 | |
| Common Stock | ||
| Title of 12(b) Security | Common Stock, $0.0001 par value | |
| Trading Symbol | IEA | |
| Security Exchange Name | NASDAQ | |
| Warrant | ||
| Title of 12(b) Security | Warrants for Common Stock | |
| Trading Symbol | IEAWW | |
| Security Exchange Name | NASDAQ |
