Allowance for Loan and Lease Loss and Credit Quality (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Deferred loan fees	$ (31,700,000)	$ (26,300,000)	$ (4,700,000)
Financing Receivable Modifications Recorded Investments	64,906,000	66,696,000
Restructured Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable Modifications Recorded Investments	60,900,000	54,800,000
Percentage of loan collateral balance	100.00%
Available commitments for troubled debt restructurings outstanding	$ 3,800,000	$ 1,000,000
Homogeneous [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Duration of time account is past due before risk rating is applied	30 days
Minimal Risk [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	1
Low Risk [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	2
Modest Risk [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	3
Average Risk [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	4
Acceptable Risk [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	5
Pass/Watch [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	6
Special Mention [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	7
Special Mention [Member] | Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	7
Special Mention [Member] | Homogeneous [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	30 days
Special Mention [Member] | Homogeneous [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	59 days
Special Mention [Member] | Homogeneous Retail [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	7
Special Mention [Member] | Homogeneous Retail [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	30 days
Special Mention [Member] | Homogeneous Retail [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	89 days
Substandard [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	8
Substandard [Member] | Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	8
Substandard [Member] | Homogeneous [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	60 days
Substandard [Member] | Homogeneous [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	89 days
Substandard [Member] | Homogeneous Retail [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	8
Substandard [Member] | Homogeneous Retail [Member] | Open-End Loan [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	90 days
Substandard [Member] | Homogeneous Retail [Member] | Open-End Loan [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	180 days
Substandard [Member] | Homogeneous Retail [Member] | Closed-End Loan [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	90 days
Substandard [Member] | Homogeneous Retail [Member] | Closed-End Loan [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	120 days
Doubtful [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	9
Doubtful [Member] | Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	9
Doubtful [Member] | Homogeneous [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	90 days
Doubtful [Member] | Homogeneous [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	179 days
Loss [Member] | Non-Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	10
Loss [Member] | Homogeneous [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	10
Loss [Member] | Homogeneous [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	180 days
Loss [Member] | Homogeneous Retail [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Internal risk rating code	10
Loss [Member] | Homogeneous Retail [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	120 days
Loss [Member] | Homogeneous Retail [Member] | Maximum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	180 days
Loss [Member] | Homogeneous Retail [Member] | Open-End Loan [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	180 days
Loss [Member] | Homogeneous Retail [Member] | Closed-End Loan [Member] | Minimum [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Days past due on account for qualifying credit quality indicator	120 days