Loans and the Allowance for Loan and Lease Losses (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Loans and the Allowance for Loan and Lease Losses (Details) [Line Items]
Number of Segments of Loans and Leases	5
Non Accrual Contractual Due	90 years
Threshold to Determine Impaired Loans	$ 250,000
Period Considered to Calculate Actual Loss	3 years
Loans Pledged as Collateral	1,100,000,000		1,000,000,000
Financing Receivable, Collectively Evaluated for Impairment	2,616,330,000		2,520,693,000
Commitments to Lend Additional Funds	0
Financing Receivable, Modifications, Recorded Investment	2,800,000		2,800,000
Loans Modified In Troubled Debt Restructuring On Non Accrual Status	1,100,000		1,000,000
Financing Receivable, Modifications, Number of Contracts	0
Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down	0	333,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0
Acquired Loans [Member]
Loans and the Allowance for Loan and Lease Losses (Details) [Line Items]
Financing Receivable, Collectively Evaluated for Impairment	$ 1,100,000,000		$ 1,200,000,000