Shareholders' Equity And Earnings Per Share (Narrative) (Detail) (USD $)	0 Months Ended	1 Months Ended					3 Months Ended		6 Months Ended		12 Months Ended				1 Months Ended					1 Months Ended		3 Months Ended				0 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended
	Dec. 19, 2008	Apr. 30, 2014	Feb. 28, 2014	Jan. 31, 2014	Feb. 28, 2013	Mar. 31, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2010	Dec. 31, 2013	Jul. 19, 2013	Dec. 07, 2010	Jul. 19, 2013 Series A Preferred Stock [Member]	Aug. 31, 2008 Series A Preferred Stock [Member]	Jun. 30, 2014 Series A Preferred Stock [Member]	Dec. 31, 2013 Series A Preferred Stock [Member]	Jun. 30, 2013 Series A Preferred Stock [Member]	Mar. 31, 2012 Series C Preferred Stock [Member]	Aug. 31, 2008 Series C Preferred Stock [Member]	Mar. 31, 2014 Series C Preferred Stock [Member]	Dec. 31, 2013 Series C Preferred Stock [Member]	Jun. 30, 2014 Series C Preferred Stock [Member]	Jun. 30, 2013 Series C Preferred Stock [Member]	Dec. 15, 2013 Equity Component	Jun. 30, 2014 Equity Component	Dec. 31, 2010 Equity Component	Jun. 30, 2014 Junior Subordinated Amortizing Notes [Member]	Dec. 31, 2013 Junior Subordinated Amortizing Notes [Member]	Dec. 31, 2010 Junior Subordinated Amortizing Notes [Member]	Dec. 15, 2013 Junior Subordinated Amortizing Notes [Member]	Mar. 15, 2011 Junior Subordinated Amortizing Notes [Member] Debt [Member]	Dec. 31, 2010 Junior Subordinated Amortizing Notes [Member] Debt [Member]	Dec. 07, 2010 Junior Subordinated Amortizing Notes [Member] Debt [Member]	May 01, 2013 First Lansing Bancorp, Inc. [Member]	Dec. 31, 2010 Minimum [Member] Equity Component	Dec. 31, 2010 Maximum [Member] Equity Component	Jun. 30, 2014 US Treasury [Member]	Jun. 30, 2014 Other Warrants [Member]
Temporary Equity [Line Items]
Amount Of Tangible Equity Units Sold														4,600,000
Rate on tangible equity units														7.50%
Tangible equity unit public offering price per unit														$ 50.00
Net proceeds on sale of tangible equity units											$ 222,700,000
Maturity Date																												Dec. 15, 2013	Dec. 15, 2013		Dec. 15, 2013			Dec. 15, 2013
Debt Instrument, Frequency of Periodic Payment																														quarterly				quarterly
Percentage of fair value of debt component quarterly cash payments																																		7.50%
Discount rate on debt component																																			9.50%
Risk-free rate																												0.95%
Expected stock price volatility minimum																																					35.00%	45.00%
Percent of dividend yield plus stock borrow cost																												0.85%
Equity term, years																												3 years 7 days
Junior subordinated amortizing note, initial principal amount																																			9.728182
Contractual rate																																9.50%			9.50%
Quarterly installments on amortizing note																																	0.989583	0.9375
Settlement rate, shares																										1.3333
Number Of Consecutive Trading Days																											20
Amount Per Share Reclassified From Surplus To Common Stock																										$ 1.00
Preferred stock, shares issued																50,000	0	0	50,000	126,500			126,477	126,467	126,500
Preferred stock, liquidation value per share																$ 1,000	$ 1,000	$ 1,000	$ 1,000	$ 1,000			$ 1,000	$ 1,000	$ 1,000
Preferred stock, value																$ 50,000,000	$ 0	$ 0	$ 49,976,000	$ 126,500,000			$ 126,477,000	$ 126,467,000	$ 126,500,000
Preferred Stock, Dividend Payment Terms																quarterly					quarterly
Preferred stock, dividend rate, percentage																8.00%				5.00%
Convertible Preferred Stock, Terms of Conversion																38.88				24.3132
Preferred Stock, Shares Converted															50,000							10	23
Stock Issued During Period, Shares, Conversion of Convertible Securities															1,944,000							244	558
Common stock, no par value													$ 0
Warrants outstanding	1,643,295					19,000																																	1,143,366	0
Investment Warrants, Exercise Price	$ 22.82
Warrant Termination Period	10 years
Warrants Exercised					1,000	18,000	499,929
Common Stock, Shares, Issued from Exercise of Warrant Shares							259,071
Warrants Holders Common Stock Purchase Price Per Share									$ 30.50
Common stock, shares issued																																				648,286
Cash dividends declared per common share		$ 0.10		$ 0.10			$ 0.10	$ 0.00	$ 0.20	$ 0.09
Common Stock Dividends Per Share Declared Annualized		$ 0.40		$ 0.40
Dividends Payable, Date to be Paid		May 22, 2014	Feb. 20, 2014
Dividends Payable, Date of Record		May 08, 2014	Feb. 06, 2014