Loans and Allowance for Credit Losses Loans Modified Under Troubled Debt Restructurings (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 63,469	$ 67,621
Non-accrual TDRs	27,230	24,616	[1]
Total TDRs	90,699	92,237
Real-estate - residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	31,584	31,308
Real-estate commercial mortage [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	17,482	18,822
Construction - Commercial Residential [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	4,482	9,241
Commercial - Secured [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	6,417	5,170
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	3,299	2,975
Commercial - unsecured [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	174	67
Consumer - direct [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	15	19
Consumer Other Financing Receivable [Member]
Financing Receivable, Modifications [Line Items]
Accruing TDRs	$ 16	$ 19

[1] Included within non-accrual loans in the preceding table detailing non-performing assets.