Mortgage Servicing Rights and Mortgage Servicing Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended			12 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Dec. 31, 2012		Sep. 30, 2013 Fair Value, Inputs, Level 3		Dec. 31, 2012 Fair Value, Inputs, Level 3	Sep. 30, 2012 Fair Value, Inputs, Level 3	Jun. 30, 2013 Citizens Republic Bancorp	Apr. 12, 2013 Citizens Republic Bancorp	Dec. 31, 2012 Citizens Republic Bancorp	Jun. 30, 2012 Citizens Republic Bancorp	Dec. 31, 2011 Citizens Republic Bancorp
Mortage Servicing Rights Amortized Value [Roll Forward]
Mortgage Servicing Rights Beginning of Period	$ 22,604		$ 21,273	$ 21,316		$ 21,179	$ 21,179						$ 0	$ 1,100	$ 1,065	$ 0	$ 0
Mortgage Servicing Rights Additions	1,450		1,408	4,151		4,597
Amortization of Mortgage Servicing Rights (MSRs)	(1,131)		1,390	(3,609)		4,485
Mortgage Servicing Rights, End of Period	22,923		21,291	22,923		21,291	21,316						0	1,100	1,065	0	0
Mortage Servicing Rights Valuation Rollforward [Roll Forward]
Mortgage Servicing rights Valuation Allowance Beginning of Period	(482)		(3,488)	(2,564)		(3,539)	(3,539)
Mortgage Servicing Rights (MSR) Impairment (Recovery)	(90)		(590)	1,992		(539)	1,000
Mortgage Servicing rights Valuation Allowance, End of Period	(572)		(4,078)	(572)		(4,078)	(2,564)
Mortgage Servicing Rights Net Carrying balance	22,351		17,213	22,351		17,213	18,800
Fair Value of Mortgage Servicing Rights	$ 22,616	[1]	$ 17,294	$ 22,616	[1]	$ 17,294	$ 18,833	[1]	$ 22,616	[1]	$ 18,833	$ 17,294

[1] (b) - MSRs with a recorded investment of $22.9 million were reduced by a specific valuation allowance totaling $0.6 million to a reported carrying value of $22.4 million resulting in recognition of $0.1 million in recoveries included in loans sales and servicing income in the three months ended September 30, 2013.