Fair Value Fair Value (Impaired Financing Receivables Additional Information) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Book Value Of Impaired Loans Carried At Fair Value	$ 11,660	$ 11,783
Partial Charge-Offs On Impaired Loans carried at Fair Value	10,463	10,512
Impaired Financing Receivable, Related Allowance	4,930	4,191
impaired Financing Receivable, loans not held at Fair Value, Carrying Amount	64,041	66,977
Impaired Financing Receivable, Recorded Investment	78,171	80,664	$ 70,492
Impaired Loan Fair Value	9,200	9,496
Impaired Financing Receivable, loans not held at Fair Value, Recorded Investment	66,511	68,881
Partial Charge-offs on Impaired Loans carried at Cost	17,959	18,193
Impaired Financing Receivable, Carrying Value	73,241	76,473
Partial Charge-Offs On Impaired Loans	28,422	28,705
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	4,930	4,191
Financing Receivable, not collateral dependent [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	2,470	1,904
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	$ 2,460	$ 2,287