Goodwill and Other Intangible Assets (Details Textual) (USD $)				6 Months Ended						6 Months Ended			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014 Core Deposits	Jun. 30, 2014 Customer Relationships	Dec. 31, 2013 Customer Relationships	Jun. 30, 2013 Customer Relationships	Apr. 12, 2013 Citizens Republic Bancorp		Jun. 30, 2014 Citizens Republic Bancorp Core Deposits	Apr. 12, 2013 Citizens Republic Bancorp Core Deposits		Jun. 30, 2014 Citizens Republic Bancorp Customer Relationships	Apr. 12, 2013 Citizens Republic Bancorp Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets					$ 14,000,000	$ 14,000,000	$ 14,000,000	$ 84,774,000	[1]		$ 70,800,000	[1]		$ 14,000,000	[1]
Goodwill	741,740,000	741,740,000	741,740,000
Finite-Lived Intangible Asset, Useful Life				10 years						15 years			12 years
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	5,900,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	10,400,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	9,200,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	8,200,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	$ 7,300,000

[1] Intangible assets consist of core deposit intangibles of $70.8 million and trust relationships of approximately $14.0 million. The useful lives for which the core deposit intangibles and the trust relationships are being amortized over is 15 years and 12 years, respectively.