Fair Value Fair Value (Impaired Financing Receivables Additional Information) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Book Value Of Impaired Loans Carried At Fair Value	$ 3,820	$ 6,503
Partial Charge-Offs On Impaired Loans carried at Fair Value	3,126	3,630
Impaired Financing Receivable, Related Allowance	3,083	2,273
impaired Financing Receivable, loans not held at Fair Value, Carrying Amount	67,716	39,472
Impaired Financing Receivable, Recorded Investment	74,478	48,144	$ 46,760
Impaired Loan Fair Value	3,679	6,399
Impaired Financing Receivable, loans not held at Fair Value, Recorded Investment	70,658	41,641
Partial Charge-offs on Impaired Loans carried at Cost	2,507	7,616
Impaired Financing Receivable, Carrying Value	71,395	45,871
Partial Charge-Offs On Impaired Loans	5,633	11,246
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	3,083	2,273
Financing Receivable, not collateral dependent [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	2,942	2,169
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	$ 141	$ 104