Mortgage Servicing Rights and Mortgage Servicing Activity (Changes in the Carrying Amount of Mortgage Servicing Rights) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Level 3	Dec. 31, 2012 Level 3	Dec. 31, 2011 Level 3	Apr. 12, 2013 Citizens Republic Bancorp	Apr. 12, 2013 Mortgage Servicing Rights [Member] Citizens Republic Bancorp	Dec. 31, 2012 Mortgage Servicing Rights [Member] Citizens Republic Bancorp	Dec. 31, 2011 Mortgage Servicing Rights [Member] Citizens Republic Bancorp
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets							$ 680,020	$ 994	$ 0	$ 0
Mortage Servicing Rights Amortized Value [Roll Forward]
Mortgage Servicing Rights Beginning of Period	21,316	21,179	21,317
Mortgage Servicing Rights Additions	4,952	5,876	4,442
Amortization of Mortgage Servicing Rights (MSRs)	(4,502)	(5,739)	(4,580)
Mortgage Servicing Rights, End of Period	22,760	21,316	21,179
Mortage Servicing Rights Valuation Rollforward [Roll Forward]
Mortgage Servicing rights Valuation Allowance Beginning of Period	(2,564)	(3,539)	0
Mortgage Servicing Rights (MSR) Impairment (Recovery)	2,282	975	(3,539)
Mortgage Servicing rights Valuation Allowance, End of Period	(282)	(2,564)	(3,539)
Mortgage Servicing Rights Net Carrying balance	22,478	18,752	17,640
Fair Value of Mortgage Servicing Rights	$ 23,041	$ 18,833		$ 23,041	$ 18,833	$ 17,749