A common standard is 10 years employment history. Many employers ask for this on applications. Three to five years would be a little short. Pattie is also right on with a one line summary for older jobs or those with no relevance. A one liner for military service should always be noted somewhere on the resume, especially with an Honorable Discharge. We recommend this to veteran job seekers in our workforce region. Of course this is different for a federal job - complete expansive history is the rule.