Subsequent Events (Detail) (Subsequent Event [Member], USD $) In Millions, unless otherwise specified	0 Months Ended
	Apr. 28, 2014 Policy Billing Services Inc. & Equity Premium Finance Inc. [Member]	Apr. 08, 2014 Talmer Bank & Trust [Member] locations	Apr. 07, 2014 THE National Bank [Member]	Apr. 07, 2014 Performing Financing Receivable [Member] THE National Bank [Member]
Subsequent Event [Line Items]
Business Acquisition, Effective Date of Acquisition	Apr. 28, 2014	Apr. 08, 2014	Apr. 07, 2014
Business Acquisition, Percentage of Voting Interests Acquired	100.00%
Number of Affiliated Companies Acquired	2
Number of locations		11
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deposits		$ 360.0	$ 40.0
Business Combination, Acquired Receivables, Fair Value				$ 90.0