Mergers and Acquisitions-Fair Value Adjustments (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 01, 2013
Business Acquisition [Line Items]
Deal charges	$ 694	$ 6,027	$ 0
Goodwill	274,706	276,100	184,859
First M&F
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
Securities				253
Loans, net of First M&F's allowance for loan losses				(45,761)	[1]
Fixed assets				(3,254)
Core deposits intangible, net of First M&F’s existing core deposit intangible				21,158
Other real estate owned				(5,797)	[1]
Other assets				(443)	[1]
Deposits				(3,207)
Junior subordinated debentures				12,371
Other liabilities				1,748
Deferred income taxes				10,210
Total net assets acquired				66,718
Goodwill				$ 90,127	[2]

[1] 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.

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