Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					3 Months Ended	9 Months Ended	12 Months Ended			9 Months Ended	12 Months Ended						12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Sep. 15, 2012	Jan. 31, 2011	Sep. 30, 2011 Restricted Stock Awards [Member]	Sep. 30, 2012 Restricted Stock Awards [Member]	Dec. 31, 2012 Restricted Stock Awards [Member]	Dec. 31, 2011 Restricted Stock Awards [Member]	Dec. 31, 2010 Restricted Stock Awards [Member]	Sep. 30, 2012 Restricted Stock Units [Member]	Dec. 31, 2012 Restricted Stock Units [Member]	Dec. 31, 2012 Stock Compensation Plan [Member]	Dec. 31, 2011 Stock Compensation Plan [Member]	Dec. 31, 2010 Stock Compensation Plan [Member]	Sep. 15, 2012 Indiana Community Bancorp [Member]	Jan. 31, 2011 Monroe Bancorp [Member]	Dec. 31, 2012 Minimum [Member] Restricted Stock Awards [Member]	Dec. 31, 2012 Minimum [Member] Stock Compensation Plan [Member]	Dec. 31, 2012 Maximum [Member] Restricted Stock Awards [Member]	Dec. 31, 2012 Maximum [Member] Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares available for issuance	3,500,000
Stock based compensation expense	$ 3.3	$ 3.4	$ 2.4			$ (0.1)
Total income tax benefit, stock-based compensation cost	1.3	1.4	0.9
Share-based compensation awards, vesting period							36 months				36 months	3 years						3 years	3 years	5 years	5 years
Contractual term, in years	0 years	0 years	0 years										10 years
Unrecognized compensation expense								1.2				2.9		2.4	1.8
Expected weighted-average period for cost recognition (in years)	1 month 2 days							1 year 8 months 19 days				1 year 8 months 12 days
Total fair value of shares vested								$ 1.9	$ 1.0	$ 1.3
Options outstanding	3,371,000	4,664,000		300,000	300,000											200,000	300,000
Number of shares impacted by modification of vesting eligibility						10,000