Allowance for Credit Losses (Narrative) (Details) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020 USD ($) risk_code	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) risk_code	Sep. 30, 2019 USD ($)	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2019 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items]
Length of time projected by model				10 years
Model evaluation adjustment | $		$ 40,600		$ 40,600
Model evaluation adjustment due to RUC | $		5,000		5,000
Interest Income on Non-Accrual Loans and Leases | $		0		$ 0
Days Past Due on Leases and Equipment Finance				181 days
Loans Deferred Under CARES Act | $		782,300		$ 782,300
Total troubled debt restructurings, net of deferred fees and costs | $		$ 15,800		$ 15,800				$ 18,600
Minimum Collateral Value compared to Secured Loan (Percent)		100.00%		100.00%
Financing receivables modified as troubled debt restructurings within the previous 12 months | $		$ 132	$ 0	$ 9,600	$ 0
Consensus scenario
Financing Receivable, Allowance for Credit Loss [Line Items]
Unemployment Rate		10.70%
Moody's Analytics August S2 scenario
Financing Receivable, Allowance for Credit Loss [Line Items]
Unemployment Rate		10.20%
Probability economy performs better than scenario		75.00%
Probability economy performs worse than scenario		25.00%
Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Maturity date extension				1 month
Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Maturity date extension				6 months
Non homogeneous
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Threshold Period Past Due		90 days		90 days
Pass | Non homogeneous | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		1		1
Pass | Non homogeneous | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		9		9
Watch | Non homogeneous | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		10		10
Watch | Non homogeneous | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		11		11
Special mention | Non homogeneous
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		12		12
Substandard | Non homogeneous | Minimum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		13		13
Substandard | Non homogeneous | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		14		14
Doubtful | Non homogeneous
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		15		15
Loss | Non homogeneous
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		16		16
Loss | Non homogeneous | Maximum
Financing Receivable, Allowance for Credit Loss [Line Items]
Internal risk rating code (number)		16		16
Expected | Consensus scenario
Financing Receivable, Allowance for Credit Loss [Line Items]
Unemployment Rate	9.30%						5.00%
Expected | Moody's Analytics August S2 scenario
Financing Receivable, Allowance for Credit Loss [Line Items]
Unemployment Rate	10.40%					5.00%