Allowance for Loan Losses Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary of Loans Restructured and Subsequently Defaulted Under the Restructured Terms) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 contracts		Dec. 31, 2013 contracts		Dec. 31, 2012 contracts
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	21	[1],[2],[3]	35	[1],[2],[3]	75	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 11,967	[1],[2],[3]	$ 22,680	[1],[2],[3]	$ 72,512	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	6	[3],[4]	5	[3],[4]	18	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2,127	[3],[4]	2,683	[3],[4]	20,553	[3],[4]
Residential real estate and other
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	6	[1],[2],[3]	10	[1],[2],[3]	10	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	1,836	[1],[2],[3]	2,296	[1],[2],[3]	1,638	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[3],[4]	0	[3],[4]	5	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	211	[3],[4]	0	[3],[4]	1,168	[3],[4]
Commercial and industrial | Commercial
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	2	[1],[2],[3]	6	[1],[2],[3]	18	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	1,549	[1],[2],[3]	708	[1],[2],[3]	14,311	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[3],[4]	1	[3],[4]	4	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	88	[3],[4]	20	[3],[4]	9,925	[3],[4]
Residential construction | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	[1],[2],[3]	0	[1],[2],[3]	3	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	[1],[2],[3]	0	[1],[2],[3]	2,147	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[3],[4]	0	[3],[4]	0	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	[3],[4]	0	[3],[4]	0	[3],[4]
Commercial construction | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	[1],[2],[3]	3	[1],[2],[3]	2	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	[1],[2],[3]	6,120	[1],[2],[3]	622	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[3],[4]	0	[3],[4]	2	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	[3],[4]	0	[3],[4]	622	[3],[4]
Land | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	0	[1],[2],[3]	3	[1],[2],[3]	17	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	0	[1],[2],[3]	2,639	[1],[2],[3]	31,836	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[3],[4]	1	[3],[4]	2	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	[3],[4]	215	[3],[4]	3,786	[3],[4]
Office | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	2	[1],[2],[3]	4	[1],[2],[3]	0	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	1,510	[1],[2],[3]	4,021	[1],[2],[3]	0	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[3],[4]	1	[3],[4]	0	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	[3],[4]	1,648	[3],[4]	0	[3],[4]
Industrial | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	2	[1],[2],[3]	1	[1],[2],[3]	1	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	1,763	[1],[2],[3]	949	[1],[2],[3]	727	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[3],[4]	0	[3],[4]	0	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	1,078	[3],[4]	0	[3],[4]	0	[3],[4]
Retail | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	1	[1],[2],[3]	1	[1],[2],[3]	8	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	202	[1],[2],[3]	200	[1],[2],[3]	13,518	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[3],[4]	0	[3],[4]	1	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	[3],[4]	0	[3],[4]	3,607	[3],[4]
Multi-family | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	1	[1],[2],[3]	1	[1],[2],[3]	1	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	181	[1],[2],[3]	705	[1],[2],[3]	380	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[3],[4]	1	[3],[4]	0	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	181	[3],[4]	705	[3],[4]	0	[3],[4]
Mixed use and other | Commercial real-estate
Financing Receivables, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts	7	[1],[2],[3]	6	[1],[2],[3]	15	[1],[2],[3]
Financing Receivable, Modifications, Post-Modification Recorded Investment	4,926	[1],[2],[3]	5,042	[1],[2],[3]	7,333	[1],[2],[3]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	2	[3],[4]	1	[3],[4]	4	[3],[4]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 569	[3],[4]	$ 95	[3],[4]	$ 1,445	[3],[4]

[1] TDRs may have more than one modification representing a concession. As such, TDRs during the period may be represented in more than one of the categories noted above.

[2] Total TDRs represent all loans restructured in TDRs during the year indicated.

[3] Balances represent the recorded investment in the loan at the time of the restructuring.

[4] TDRs considered to be in payment default are over 30 days past-due subsequent to the restructuring.