Officials with Albertsons confirmed Friday that hackers broke into their credit and debit card databases.
But a statement from the company insisted the "intrusion" was contained and it was "confident that its customers can safely use their credit and debit cards in its stores."
Albertsons did not mention exactly which stores were affected, but company officials said Friday that more than 700 of its 1,060 locations were impacted.
In addition to Idaho, Albertsons operates locations in California, Montana, North Dakota, Nevada, Oregon, Washington, Wyoming and Utah.
Compromised information includes names, account numbers and expiration dates.
The data breach started as early as June 22 and ended July 17, according to Albertsons officials.
Federal law enforcement has already launched an investigation into the matter.
Albertsons is offering a year of complimentary identity-protection services to customers who may have been affected by identity thieves. Customers can call 1-877-932-7948 or visit albertsons.com for details.