Goodwill and Other Intangible Assets (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended				3 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Core Deposits	Dec. 31, 2013 Citizens Republic Bancorp	Apr. 12, 2013 Citizens Republic Bancorp	Dec. 31, 2013 Citizens Republic Bancorp Core Deposits	Apr. 12, 2013 Citizens Republic Bancorp Core Deposits	Dec. 31, 2013 Citizens Republic Bancorp Customer Relationships	Apr. 12, 2013 Citizens Republic Bancorp Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						$ 84,774		$ 70,800	$ 14,000	$ 14,000
Finite-Lived Intangible Asset, Useful Life				10 years			15 years		12 years
Goodwill	739,819	460,044	460,044
Goodwill, Acquired During Period					279,775
Amortization of Intangible Assets	$ 8,392	$ 1,866	$ 2,172