Income Taxes (Summary Of Differences In Taxes Computed At Statutory Rate) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Provision at statutory rate of 35%									$ 44,725	$ 34,917	$ 15,218
Tax-exempt interest									15,722	13,571	16,294
Section 291/265 interest disallowance									147	213	329
Bank owned life insurance income									6,452	5,322	4,052
Tax-exempt income									(10,701)	(9,685)	(10,149)
Reserve for unrecognized tax benefits									(292)	(623)	(652)
State income taxes									3,409	3,188	518
Other, net									(1,031)	(495)	331
Provision for income taxes	11,020	5,861	10,889	8,340	8,812	8,045	5,927	4,518	36,110	27,302	5,266
Effective tax rate									28.30%	27.40%	12.10%
Statutory rate									35.00%
Old National Bancorp [Member]
Provision for income taxes									(5,909)	(3,819)	(7,833)
Tax-Exempt Income [Member]
Tax-exempt interest									(8,590)	(8,035)	(9,060)
Bank owned life insurance income									$ (2,258)	$ (1,863)	$ (1,418)