Loans (Summary Of Gross Loans Held For Investment By Year Of Origination And Internally Assigned Credit Grade) (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Financing Receivable, Recorded Investment [Line Items]
2020	$ 90,758
2019	263,570
2018	180,695
2017	117,032
2016	79,035
Prior	84,824
Revolving loans at amortized cost	1,160,210
Financing Receivable, before Allowance for Credit Loss, Total	1,976,124
SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	4,138
2019	9,479
2018	14,115
2017	8,067
2016	10,728
Prior	15,487
Financing Receivable, before Allowance for Credit Loss, Total	62,014
SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	10,842
2019	58,092
2018	40,063
2017	35,014
2016	29,104
Prior	46,634
Financing Receivable, before Allowance for Credit Loss, Total	219,749
SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	13,148
2018	23,603
2017	8,425
2016	3,647
Financing Receivable, before Allowance for Credit Loss, Total	48,823
Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	75,778
2019	179,098
2018	95,807
2017	58,140
2016	28,132
Prior	9,012
Financing Receivable, before Allowance for Credit Loss, Total	445,967
SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	927,613
Financing Receivable, before Allowance for Credit Loss, Total	927,613
IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	228,820
Financing Receivable, before Allowance for Credit Loss, Total	228,820
Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	3,753
2018	7,107
2017	7,369
2016	7,424
Prior	13,462
Financing Receivable, before Allowance for Credit Loss, Total	39,115
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
2017	17
Prior	229
Revolving loans at amortized cost	3,777
Financing Receivable, before Allowance for Credit Loss, Total	4,023
Non-Rated [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	1,936
Financing Receivable, before Allowance for Credit Loss, Total	1,936
Non-Rated [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	2,529
Financing Receivable, before Allowance for Credit Loss, Total	2,529
Non-Rated [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	15,021
2019	1,549
2018	556
Financing Receivable, before Allowance for Credit Loss, Total	17,126
Non-Rated [Member] | SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	14,819
Financing Receivable, before Allowance for Credit Loss, Total	14,819
Non-Rated [Member] | IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	55,921
Financing Receivable, before Allowance for Credit Loss, Total	55,921
Non-Rated [Member] | Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	194
2018	283
2017	649
Financing Receivable, before Allowance for Credit Loss, Total	1,126
Non-Rated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
2017	17
Prior	229
Revolving loans at amortized cost	1,970
Financing Receivable, before Allowance for Credit Loss, Total	2,216
Pass [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	2,202
2019	9,430
2018	12,922
2017	7,262
2016	8,134
Prior	12,657
Financing Receivable, before Allowance for Credit Loss, Total	52,607
Pass [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	8,313
2019	58,092
2018	40,063
2017	35,014
2016	29,028
Prior	38,929
Financing Receivable, before Allowance for Credit Loss, Total	209,439
Pass [Member] | SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	13,148
2018	23,603
2017	8,425
2016	2,936
Financing Receivable, before Allowance for Credit Loss, Total	48,112
Pass [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	60,757
2019	161,908
2018	92,587
2017	56,292
2016	26,452
Prior	8,748
Financing Receivable, before Allowance for Credit Loss, Total	406,744
Pass [Member] | SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	912,794
Financing Receivable, before Allowance for Credit Loss, Total	912,794
Pass [Member] | IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	172,899
Financing Receivable, before Allowance for Credit Loss, Total	172,899
Pass [Member] | Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	3,559
2018	6,824
2017	6,720
2016	7,424
Prior	13,462
Financing Receivable, before Allowance for Credit Loss, Total	37,989
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	1,485
Financing Receivable, before Allowance for Credit Loss, Total	1,485
Special Mention [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2018	1,193
2017	44
2016	541
Prior	985
Financing Receivable, before Allowance for Credit Loss, Total	2,763
Special Mention [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Prior	264
Financing Receivable, before Allowance for Credit Loss, Total	264
Substandard [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	49
2017	761
2016	2,053
Prior	1,845
Financing Receivable, before Allowance for Credit Loss, Total	4,708
Substandard [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2016	76
Prior	7,441
Financing Receivable, before Allowance for Credit Loss, Total	7,517
Substandard [Member] | SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2016	711
Financing Receivable, before Allowance for Credit Loss, Total	711
Substandard [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	15,641
2018	2,664
2017	1,848
2016	1,680
Prior	264
Financing Receivable, before Allowance for Credit Loss, Total	22,097
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	322
Financing Receivable, before Allowance for Credit Loss, Total	$ 322