Document and Entity Information
| Document and Entity Information | Dec. 10, 2019 |
| Cover [Abstract] | |
| Entity Registrant Name | PACKAGING CORP OF AMERICA |
| Amendment Flag | true |
| Entity Central Index Key | 0000075677 |
| Document Type | 8-K/A |
| Document Period End Date | Dec. 10, 2019 |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-15399 |
| Entity Tax Identification Number | 36-4277050 |
| Entity Address, Address Line One | 1955 West Field Court |
| Entity Address, City or Town | Lake Forest |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60045 |
| City Area Code | (847) |
| Local Phone Number | 482-3000 |
| 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 | PKG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Amendment Description | On December 13, 2019, PCA filed a Current Report on Form 8-K (the “December 2019 Report”), reporting that Donna A. Harman was elected to the board of directors on December 10, 2019. PCA hereby amends the December 2019 Report and reports that, on February 25, 2020: (1) Ms. Harman was determined by the board of directors to be independent; and (2) Ms. Harman was elected to the audit committee of the board of directors. All other information included in the December 2019 Report remains unchanged. |