Loans and Allowance for Credit Losses Loans Modified Under Troubled Debt Restructurings (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	$ 74,331		$ 85,509
Non-accrual TDRs	30,377	[1]	31,244	[1]
Total TDRs	104,708		116,753
Real-estate - residential mortgage [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	28,948		32,993
Real-estate commercial mortage [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	24,828		34,672
Commercial - Secured [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	8,264		5,624
Construction - Commercial Residential [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	10,599		10,564
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	1,549		1,518
Commercial - unsecured [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	130		121
Consumer - direct [Member]
Financing Receivable, Modifications [Line Items]
Total accruing TDRs	$ 13		$ 17

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