Loans and Leases Held for Investment, Net of Allowance For Loan and Lease Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Term Loans and Leases by Origination Year
Total	$ 2,707,992	$ 0
Consumer Portfolio Segment
Term Loans and Leases by Origination Year
2021	1,440,563
2020	89,436
2019	65,149
2018	51,091
2017	8,434
Prior	59,287
Within Revolving Period	1,278
Total	1,715,238
Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
2021	1,258,279
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	1,258,279
Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
2021	17,210
2020	40,108
2019	28,246
2018	8,522
2017	3,044
Prior	42,804
Within Revolving Period	1,266
Total	141,200
Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
2021	163,866
2020	49,328
2019	36,903
2018	42,569
2017	5,390
Prior	16,483
Within Revolving Period	0
Total	314,539
Consumer Portfolio Segment | Other consumer
Term Loans and Leases by Origination Year
2021	1,208
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	12
Total	1,220
Commercial Portfolio Segment
Term Loans and Leases by Origination Year
2021	364,423
2020	271,215
2019	131,145
2018	78,728
2017	51,535
Prior	91,305
Within Revolving Period	4,403
Total	992,754
Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
2021	47,140
2020	38,074
2019	33,378
2018	19,551
2017	7,069
Prior	12,245
Within Revolving Period	0
Total	157,457
Commercial Portfolio Segment | Equipment finance | Pass
Term Loans and Leases by Origination Year
2021	45,557
2020	38,074
2019	31,501
2018	18,807
2017	7,069
Prior	12,245
Within Revolving Period	0
Total	153,253
Commercial Portfolio Segment | Equipment finance | Special mention
Term Loans and Leases by Origination Year
2021	1,583
2020	0
2019	1,877
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	3,460
Commercial Portfolio Segment | Equipment finance | Substandard
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	744
2017	0
Prior	0
Within Revolving Period	0
Total	744
Commercial Portfolio Segment | Equipment finance | Doubtful
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
Commercial Portfolio Segment | Equipment finance | Loss
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
2021	39,315
2020	65,353
2019	67,654
2018	47,602
2017	24,725
Prior	67,804
Within Revolving Period	3,682
Total	316,135
Commercial Portfolio Segment | Commercial real estate | Pass
Term Loans and Leases by Origination Year
2021	39,315
2020	56,981
2019	67,376
2018	43,745
2017	23,042
Prior	52,324
Within Revolving Period	3,682
Total	286,465
Commercial Portfolio Segment | Commercial real estate | Special mention
Term Loans and Leases by Origination Year
2021	0
2020	8,372
2019	0
2018	1,369
2017	1,032
Prior	10,506
Within Revolving Period	0
Total	21,279
Commercial Portfolio Segment | Commercial real estate | Substandard
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	278
2018	2,488
2017	651
Prior	4,397
Within Revolving Period	0
Total	7,814
Commercial Portfolio Segment | Commercial real estate | Doubtful
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
Commercial Portfolio Segment | Commercial real estate | Loss
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	577
Within Revolving Period	0
Total	577
Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
2021	277,968
2020	167,788
2019	30,113
2018	11,575
2017	19,741
Prior	11,256
Within Revolving Period	721
Total	519,162
Commercial Portfolio Segment | Commercial and industrial | Pass
Term Loans and Leases by Origination Year
2021	277,968
2020	166,667
2019	26,858
2018	8,283
2017	17,604
Prior	8,431
Within Revolving Period	628
Total	506,439
Commercial Portfolio Segment | Commercial and industrial | Special mention
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	2,256
2018	650
2017	554
Prior	40
Within Revolving Period	0
Total	3,500
Commercial Portfolio Segment | Commercial and industrial | Substandard
Term Loans and Leases by Origination Year
2021	0
2020	1,121
2019	999
2018	2,590
2017	1,579
Prior	1,722
Within Revolving Period	93
Total	8,104
Commercial Portfolio Segment | Commercial and industrial | Doubtful
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
Commercial Portfolio Segment | Commercial and industrial | Loss
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	52
2017	4
Prior	1,063
Within Revolving Period	0
Total	1,119
Current-29 | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
2021	1,255,020
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	1,255,020
Current-29 | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
2021	17,210
2020	40,108
2019	28,246
2018	7,848
2017	2,700
Prior	41,889
Within Revolving Period	1,266
Total	139,267
Current-29 | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
2021	163,820
2020	49,328
2019	36,903
2018	37,062
2017	5,008
Prior	16,483
Within Revolving Period	0
Total	308,604
Current-29 | Consumer Portfolio Segment | Other consumer
Term Loans and Leases by Origination Year
2021	1,208
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	12
Total	1,220
Current-29 | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	913,744
Current-29 | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	157,457
Current-29 | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	315,355
Current-29 | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	440,932
30-59 days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
2021	1,806
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	1,806
30-59 days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
30-59 days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
2021	46
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	46
30-59 days past due | Consumer Portfolio Segment | Other consumer
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
30-59 days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	385
30-59 days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	0
30-59 days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	163
30-59 days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	222
60-89 days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
2021	849
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	849
60-89 days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	93
Prior	0
Within Revolving Period	0
Total	93
60-89 days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	2,401
2017	0
Prior	0
Within Revolving Period	0
Total	2,401
60-89 days past due | Consumer Portfolio Segment | Other consumer
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
60-89 days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	76,788
60-89 days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	0
60-89 days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	143
60-89 days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	76,645
90 or more days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
2021	604
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	604
90 or more days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	674
2017	251
Prior	915
Within Revolving Period	0
Total	1,840
90 or more days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	3,106
2017	382
Prior	0
Within Revolving Period	0
Total	3,488
90 or more days past due | Consumer Portfolio Segment | Other consumer
Term Loans and Leases by Origination Year
2021	0
2020	0
2019	0
2018	0
2017	0
Prior	0
Within Revolving Period	0
Total	0
90 or more days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	1,837
90 or more days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	0
90 or more days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	474
90 or more days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	$ 1,363