Loans and Allowance for Loan Losses - Summary of net charge offs of assets sold in bulk sale transaction (Details 2) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Financing Receivable, Impaired [Line Items]
Recorded Investment	$ 130,914
Net Sales Proceeds	77,458
Net Charge-offs	(53,456)
Impaired Loans Considered
Financing Receivable, Impaired [Line Items]
Recorded Investment	96,829
Net Sales Proceeds	56,298
Net Charge-offs	(40,531)
Impaired Loans Not Considered
Financing Receivable, Impaired [Line Items]
Recorded Investment	25,687
Net Sales Proceeds	15,227
Net Charge-offs	(10,460)
Foreclosed Properties
Financing Receivable, Impaired [Line Items]
Recorded Investment	8,398
Net Sales Proceeds	5,933
Net Charge-offs	$ (2,465)