The 61-year-old lawmaker, who faces a court date Jan. 4, apologized in a statement issued hours after his arrest early Sunday.
"I am deeply sorry for the actions that resulted in this circumstance," Crapo said in the statement Sunday night. "I made a mistake for which I apologize to my family, my Idaho constituents and any others who have put their trust in me. I accept total responsibility and will deal with whatever penalty comes my way in this matter."
He also said he would take measures to ensure "this circumstance is never repeated."