Mergers and Acquisitions - Purchase Price Adjustment (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Sep. 01, 2013		Dec. 31, 2014
Business Acquisition [Line Items]
Deal charges	$ 478	$ 195
Goodwill resulting from merger	274,705	276,144			274,706
First M&F Merger
Business Acquisition [Line Items]
Shares issued to common shareholders (shares)			6,175,576
Purchase price per share (usd per share)			$ 25.17
Value of stock paid			155,439
Cash paid for fractional shares			17
Fair value of stock based compensation assumed			68
Deal charges			1,321
Total Purchase Price			156,845
Stockholders’ equity at 9/1/13			79,440
Total Net Assets Acquired			66,718
Goodwill resulting from merger			90,127	[1]
Deposits | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of liabilities			(3,207)
Junior Subordinated Debt | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of liabilities			12,371
Other liabilities | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of liabilities			1,748
Deferred income taxes | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of liabilities			10,210
Securities | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			253
Loans, net of First M&F's allowance for loan losses | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			(45,761)	[2]
Fixed assets | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			(3,254)
Core deposits intangible, net of First M&F’s existing core deposit intangible | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			21,158
Other real estate owned | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			(5,797)	[2]
Other assets | First M&F Merger
Business Acquisition [Line Items]
Fair value adjustment of assets			$ (443)

[1] The goodwill resulting from the merger has been assigned to the Community Banks operating segment.

[2] The fair value adjustments to acquired loans and other real estate owned reflect management’s expectations to more aggressively market and liquidate problem assets quickly.