Loans (Summary Of Gross Loans Held For Investment By Year Of Origination And Internally Assigned Credit Grade) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
2020	$ 495,337
2019	196,604
2018	140,621
2017	85,291
2016	63,317
Prior	75,346
Revolving loans at amortized cost	1,432,244
Financing Receivable, before Allowance for Credit Loss, Total	2,488,760	$ 778,200	$ 518,300
SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	215,270
2019	9,584
2018	13,709
2017	7,438
2016	9,498
Prior	13,294
Financing Receivable, before Allowance for Credit Loss, Total	268,793
SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	27,292
2019	67,566
2018	48,134
2017	39,773
2016	32,884
Prior	43,711
Financing Receivable, before Allowance for Credit Loss, Total	259,360
SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	3,061
2019	14,078
2018	9,595
2016	711
Financing Receivable, before Allowance for Credit Loss, Total	27,445
Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	219,661
2019	101,892
2018	62,815
2017	31,023
2016	13,141
Prior	2,143
Financing Receivable, before Allowance for Credit Loss, Total	430,675
SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	1,072,887
Financing Receivable, before Allowance for Credit Loss, Total	1,072,887
IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	359,357
Financing Receivable, before Allowance for Credit Loss, Total	359,357
Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	2,653
2019	3,484
2018	6,368
2017	7,042
2016	7,083
Prior	12,817
Financing Receivable, before Allowance for Credit Loss, Total	39,447
Advisor Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	26,986
Financing Receivable, before Allowance for Credit Loss, Total	26,986
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	414
2017	15
Prior	3,381
Financing Receivable, before Allowance for Credit Loss, Total	3,810
Non-Rated [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	208,252
Financing Receivable, before Allowance for Credit Loss, Total	208,252
Non-Rated [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	9,681
2019	2,938
Financing Receivable, before Allowance for Credit Loss, Total	12,619
Non-Rated [Member] | SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	206
Financing Receivable, before Allowance for Credit Loss, Total	206
Non-Rated [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	11,315
2019	3,065
2018	2,437
2017	1,256
2016	587
Prior	18
Financing Receivable, before Allowance for Credit Loss, Total	18,678
Non-Rated [Member] | SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	7,897
Financing Receivable, before Allowance for Credit Loss, Total	7,897
Non-Rated [Member] | IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	97,017
Financing Receivable, before Allowance for Credit Loss, Total	97,017
Non-Rated [Member] | Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	2,537
Financing Receivable, before Allowance for Credit Loss, Total	2,537
Non-Rated [Member] | Advisor Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	11,717
Financing Receivable, before Allowance for Credit Loss, Total	11,717
Non-Rated [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	414
2017	15
Prior	1,617
Financing Receivable, before Allowance for Credit Loss, Total	2,046
Pass [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	7,018
2019	9,541
2018	12,557
2017	6,745
2016	7,654
Prior	10,916
Financing Receivable, before Allowance for Credit Loss, Total	54,431
Pass [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	17,611
2019	64,628
2018	48,134
2017	39,773
2016	32,808
Prior	36,011
Financing Receivable, before Allowance for Credit Loss, Total	238,965
Pass [Member] | SBL Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	2,855
2019	14,078
2018	9,595
Financing Receivable, before Allowance for Credit Loss, Total	26,528
Pass [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	204,670
2019	98,781
2018	59,875
2017	28,921
2016	11,990
Prior	2,086
Financing Receivable, before Allowance for Credit Loss, Total	406,323
Pass [Member] | SBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	1,064,990
Financing Receivable, before Allowance for Credit Loss, Total	1,064,990
Pass [Member] | IBLOC [Member]
Financing Receivable, Recorded Investment [Line Items]
Revolving loans at amortized cost	262,340
Financing Receivable, before Allowance for Credit Loss, Total	262,340
Pass [Member] | Other Specialty Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	116
2019	3,484
2018	6,368
2017	7,042
2016	7,083
Prior	12,817
Financing Receivable, before Allowance for Credit Loss, Total	36,910
Pass [Member] | Advisor Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2020	15,269
Financing Receivable, before Allowance for Credit Loss, Total	15,269
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Prior	1,456
Financing Receivable, before Allowance for Credit Loss, Total	1,456
Special Mention [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2018	1,132
2016	520
Prior	716
Financing Receivable, before Allowance for Credit Loss, Total	2,368
Special Mention [Member] | SBL Commercial Mortgage [Member]
Financing Receivable, Recorded Investment [Line Items]
Prior	259
Financing Receivable, before Allowance for Credit Loss, Total	259
Special Mention [Member] | Direct Lease Financing [Member]
Financing Receivable, Recorded Investment [Line Items]
2016	8
Financing Receivable, before Allowance for Credit Loss, Total	8
Substandard [Member] | SBL Non Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
2019	43
2018	20
2017	693
2016	1,324
Prior	1,662
Financing Receivable, before Allowance for Credit Loss, Total	3,742
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]
2020	3,676
2019	46
2018	503
2017	846
2016	556
Prior	39
Financing Receivable, before Allowance for Credit Loss, Total	5,666
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Prior	308
Financing Receivable, before Allowance for Credit Loss, Total	$ 308