Loans and Allowance for Loan Losses Loans and Allowance for Loan Losses (Changes in Loss Share Receivable Table) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Changes in Loss Share Receivable [Roll Forward]
Balance at end of the period	$ 113,734,000	$ 205,664,000
Loss Share Receivable [Member]
Changes in Loss Share Receivable [Roll Forward]
Balance at beginning of period	205,664,000	290,100,000
Accretion	(34,903,000)	(40,559,000)
Increase due to impairment	14,728,000	42,552,000
FDIC reimbursement	(58,099,000)	(76,813,000)
Covered loans paid in full	(13,656,000)	(9,616,000)
Balance at end of the period	$ 113,734,000	$ 205,664,000