Loans and Asset Quality Information (Schedule of Covered Purchased Nonimpaired Loans) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Covered purchased nonimpaired loans:
Carrying amount of nonimpaired covered loans, beginning balance	$ 125,644	$ 207,167
Principal repayments	(25,051)	(50,183)
Transfers to foreclosed real estate	(1,129)	(5,061)
Transfers to non-covered loans due to expiration of loss-share agreement		(38,987)
Net loan (charge-offs) / recoveries	1,728	(3,301)
Accretion of loan discount	3,897	16,009
Balance, ending, carrying value	$ 105,089	$ 125,644