Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	May. 13, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Feb. 04, 2013
Business Acquisition [Line Items]
Payments for repurchase of warrants	$ 12,200	$ 12,150	$ 0	$ 0
Reduction in capital surplus		$ (9,200)
Preferred stock shares authorized		7,000,000
Non-cumulative perpetual preferred stock, series A		115,000
Non-cumulative perpetual preferred stock, oustanding					100,000
Antidilutive common stock equivalents		800,000	800,000	1,400,000
Citizens Republic Bancorp
Business Acquisition [Line Items]
Interest rate of non-cumulative perpetual preferred stock, series A					5.875%
FirstMerit | Citizens Republic Bancorp
Business Acquisition [Line Items]
Number of securities called by warrants	2,571,998.380
Citizens Republic Bancorp | Citizens Republic Bancorp
Business Acquisition [Line Items]
Adjusted strike price	$ 17.50