Loans and Allowance for Loan Losses (Impaired Loans) (Details) - USD ($) $ in Thousands		6 Months Ended		12 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Interest lost on nonaccrual loans		$ 700	$ 900
Loans on nonaccrual status		19,500		$ 25,300
Impaired loans, no individually reviewed for impairment		4,362		4,967
Impaired loans, individually reviewed, with no impairment		24,739		26,631
Impaired loans, individually reviewed, with impairment		4,567		7,851
Total impaired loans, excluding purchased impaired	[1]	33,668		39,449
Purchased impaired loans with subsequent deterioration		98,573		118,701
Purchased impaired loans with no subsequent deterioration		3,542		4,141
Impaired loan, individually reviewed, with impairment, associated reserves	[1]	403		418
Purchased impaired loans with subsequent deterioration		3,181		3,237
Impaired financing receivable, including deteriorated loans purchased, related allowance		3,584		3,655
Impaired financing receivable, simple average balance		36,559		43,446
Restructured loans		18,500		19,400
Performing [Member]
Financing Receivable, Impaired [Line Items]
Restructured loans		$ 14,200		$ 14,100

[1] * Included at June 30, 2015 and December 31, 2014 were $14.2 million and $14.1 million, respectively, in restructured and performing loans.