Regulatory Restrictions (Schedule Of Capital Ratios) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Old National Bancorp [Member]
Total capital to risk-weighted assets Actual, Amount	$ 823,594	$ 773,862
Total capital to risk-weighted assets Actual, Ratio	14.69%	14.99%
Total capital to risk-weighted assets For Capital Adequacy Purposes, Amount	448,390	413,082
Total capital to risk-weighted assets For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Tier 1 capital to risk-weighted assets Actual, Amount	764,224	697,534
Tier 1 capital to risk-weighted assets Actual, Ratio	13.63%	13.51%
Tier 1 capital to risk-weighted assets For Capital Adequacy Purposes, Amount	224,195	206,541
Tier 1 capital to risk-weighted assets For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 capital to average assets Actual, Amount	764,224	697,534
Tier 1 capital to average assets Actual, Ratio	8.53%	8.29%
Tier 1 capital to average assets For Capital Adequacy Purposes, Amount	358,493	336,710
Tier 1 capital to average assets For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Old National Bank [Member]
Total capital to risk-weighted assets Actual, Amount	732,081	683,368
Total capital to risk-weighted assets Actual, Ratio	13.14%	13.40%
Total capital to risk-weighted assets For Capital Adequacy Purposes, Amount	445,574	407,835
Total capital to risk-weighted assets For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total capital to risk-weighted assets For Well Capitalized Purposes, Amount	556,968	509,794
Total capital to risk-weighted assets For Well Capitalized Purposes, Ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets Actual, Amount	672,710	620,039
Tier 1 capital to risk-weighted assets Actual, Ratio	12.08%	12.16%
Tier 1 capital to risk-weighted assets For Capital Adequacy Purposes, Amount	222,787	203,917
Tier 1 capital to risk-weighted assets For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 capital to risk-weighted assets For Well Capitalized Purposes, Amount	334,181	305,876
Tier 1 capital to risk-weighted assets For Well Capitalized Purposes, Ratio	6.00%	6.00%
Tier 1 capital to average assets Actual, Amount	672,710	620,039
Tier 1 capital to average assets Actual, Ratio	7.57%	7.42%
Tier 1 capital to average assets For Capital Adequacy Purposes, Amount	355,633	334,068
Tier 1 capital to average assets For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Tier 1 capital to average assets For Well Capitalized Purposes, Amount	$ 444,541	$ 417,585
Tier 1 capital to average assets For Well Capitalized Purposes, Ratio	5.00%	5.00%