As of the 2010 United States Census, there were 17,808 people, 7,167 households, and 4,837 families residing in the county. The population density was . There were 7,924 housing units at an average density of . The racial makeup of the county was 94.8% white, 0.9% black or African American, 0.5% American Indian, 0.3% Asian, 2.0% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 4.8% of the population. In terms of ancestry, 23.0% were German, 12.6% were Irish, 9.4% were English, and 8.1% were American.