Loans Loans (Changes in the carrying amount and accretable yield for acquired impaired loans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended			12 Months Ended
	Dec. 31, 2013 Covered Loans	Dec. 31, 2012 Covered Loans	Dec. 31, 2011 Covered Loans	Dec. 31, 2013 Acquired Impaired Loans	Dec. 31, 2012 Acquired Impaired Loans	Apr. 12, 2013 Acquired Impaired Loans Citizens Republic Bancorp
Changes in the carrying amount and accretable yield for acquired impaired loans [Line Items]
Certain Loans Acquired in Transfer, Accretable Yield	$ 67,283	$ 113,288	$ 176,736	$ 136,646	$ 0	$ 131,558
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	403,692	762,386	1,128,978	601,000	0	819,715
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	(64,528)	(96,748)		(27,144)
Certain Loans Acquired in Transfer not Accounted for as Debt Securities Carrying Amount Accretion	64,528	96,748		27,144
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	34,965	38,177		46,361
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities F D I C Payments Received under Loss Sharing Agreement	(423,222)	(463,340)		(245,859)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Disposals of Loans	$ (16,442)	$ (4,877)		$ (14,129)