Loans and Allowance for Loan Losses (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable [Line Items]
Allowance for Loan and Lease Losses, Write-offs	$ 7,703,000	$ 13,344,000	$ 30,968,000
Allowance for Loan Losses, Recovery	6,634,000	10,292,000	6,873,000
Allowance for Loan and Lease Losses, Net Write-downs	1,069,000	3,052,000	24,095,000
Loans and Leases Receivable, Ratio, Allowance for Loan and Lease Losses to Loans and Leases Receivables	1.50%	2.21%	2.41%
Real estate - mortgage, 1-4 family residential [Member] | PC [Member] | Granite Corp. [Member]
Financing Receivable [Line Items]
Loans purchases	19,700,000	157,600,000
Loans purchases premium	$ 300,000	$ 1,300,000