Fair Value Fair Value (Impaired Financing Receivables Additional Information) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Book Value Of Impaired Loans Carried At Fair Value	$ 2,275	$ 2,167
Partial Charge-Offs On Impaired Loans carried at Fair Value	313	313
Impaired Financing Receivable, Related Allowance	5,531	5,230
impaired Financing Receivable, loans not held at Fair Value, Carrying Amount	78,166	70,171
Impaired Financing Receivable, Recorded Investment	85,851	77,491	$ 50,907
Impaired Loan Fair Value	2,154	2,090
Impaired Financing Receivable, loans not held at Fair Value, Recorded Investment	83,576	75,324
Partial Charge-offs on Impaired Loans carried at Cost	420	406
Impaired Financing Receivable, Carrying Value	80,320	72,261
Partial Charge-Offs On Impaired Loans	733	719
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	5,531	5,230
Financing Receivable, not collateral dependent [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	5,410	5,153
Commercial Receivables, excluding Commercial, Financial, and Agricultural [Domain]
Schedule of Impaired Financing Receivables Additional Information [Line Items]
Impaired Financing Receivable, Related Allowance	$ 121	$ 77