Basis Of Presentation (Effect On Park National Corporation's Capital Ratios) (Details)	Jun. 30, 2011
Tier 1 Leverage Ratio	9.47%
Tier 1 Risk-based Capital Ratio	13.60%
Total Risk-based Capital Ratio	16.07%
As Previously Reported [Member]
Tier 1 Leverage Ratio	9.54%
Tier 1 Risk-based Capital Ratio	13.72%
Total Risk-based Capital Ratio	16.18%
Effect Of Change [Member]
Tier 1 Leverage Ratio	(0.07%)
Tier 1 Risk-based Capital Ratio	(0.12%)
Total Risk-based Capital Ratio	(0.11%)