Loans and Leases Held for Investment at Amortized Cost, Net of Allowance for Loan and Lease Losses - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Term Loans and Leases by Origination Year
Total	$ 5,533,349	$ 5,033,154
Consumer Portfolio Segment
Term Loans and Leases by Origination Year
Year 1	1,461,296	3,064,021
Year 2	2,459,898	1,102,517
Year 3	790,867	31,465
Year 4	30,442	24,226
Year 5	23,860	4,546
Prior	34,595	33,833
Total	4,800,958	4,260,608
Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
Year 1	1,380,960	2,861,207
Year 2	2,285,881	1,005,166
Year 3	704,489	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	4,371,330	3,866,373
Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
Year 1	5	49,721
Year 2	49,346	58,353
Year 3	56,510	31,465
Year 4	30,442	21,683
Year 5	21,358	4,546
Prior	34,595	33,833
Total	192,256	199,601
Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
Year 1	80,331	153,093
Year 2	124,671	38,998
Year 3	29,868	0
Year 4	0	2,543
Year 5	2,502	0
Prior	0	0
Total	237,372	194,634
Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Year 1	60,051	220,905
Year 2	229,230	202,382
Year 3	135,315	111,040
Year 4	94,185	91,253
Year 5	83,075	57,687
Prior	130,535	89,279
Total	732,391	772,546
Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Year 1	3,596	59,227
Year 2	54,003	40,312
Year 3	34,635	25,873
Year 4	20,814	19,544
Year 5	16,631	11,919
Prior	12,394	3,444
Total	142,073	160,319
Commercial Portfolio Segment | Equipment finance | Pass
Term Loans and Leases by Origination Year
Year 1	3,596	59,227
Year 2	38,634	38,218
Year 3	32,754	25,014
Year 4	13,836	15,785
Year 5	13,458	11,880
Prior	12,394	3,444
Total	114,672	153,568
Commercial Portfolio Segment | Equipment finance | Special mention
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	15,369	2,094
Year 3	1,881	0
Year 4	6,295	3,759
Year 5	3,173	0
Prior	0	0
Total	26,718	5,853
Commercial Portfolio Segment | Equipment finance | Substandard
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	859
Year 4	683	0
Year 5	0	39
Prior	0	0
Total	683	898
Commercial Portfolio Segment | Equipment finance | Doubtful
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	0	0
Commercial Portfolio Segment | Equipment finance | Loss
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	0	0
Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Year 1	32,401	100,602
Year 2	98,217	53,445
Year 3	47,119	55,912
Year 4	52,594	53,737
Year 5	52,491	39,633
Prior	99,916	70,172
Total	382,738	373,501
Commercial Portfolio Segment | Commercial real estate | Pass
Term Loans and Leases by Origination Year
Year 1	32,401	100,602
Year 2	94,456	53,445
Year 3	38,291	47,497
Year 4	44,179	52,834
Year 5	52,001	35,992
Prior	79,403	60,976
Total	340,731	351,346
Commercial Portfolio Segment | Commercial real estate | Special mention
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	8,415
Year 4	0	260
Year 5	259	1,237
Prior	9,389	405
Total	9,648	10,317
Commercial Portfolio Segment | Commercial real estate | Substandard
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	3,761	0
Year 3	6,785	0
Year 4	8,415	643
Year 5	231	2,404
Prior	10,577	8,215
Total	29,769	11,262
Commercial Portfolio Segment | Commercial real estate | Doubtful
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	2,043	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	2,043	0
Commercial Portfolio Segment | Commercial real estate | Loss
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	547	576
Total	547	576
Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Year 1	24,054	61,076
Year 2	77,010	108,625
Year 3	53,561	29,255
Year 4	20,777	17,972
Year 5	13,953	6,135
Prior	18,225	15,663
Total	207,580	238,726
Commercial Portfolio Segment | Commercial and industrial | Pass
Term Loans and Leases by Origination Year
Year 1	24,054	61,076
Year 2	76,240	99,264
Year 3	48,898	24,726
Year 4	19,968	13,866
Year 5	9,959	5,174
Prior	12,337	10,831
Total	191,456	214,937
Commercial Portfolio Segment | Commercial and industrial | Special mention
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	770	0
Year 3	29	0
Year 4	96	483
Year 5	214	163
Prior	558	455
Total	1,667	1,101
Commercial Portfolio Segment | Commercial and industrial | Substandard
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	9,361
Year 3	4,634	4,529
Year 4	713	3,623
Year 5	3,780	797
Prior	3,688	2,820
Total	12,815	21,130
Commercial Portfolio Segment | Commercial and industrial | Doubtful
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	286	286
Total	286	286
Commercial Portfolio Segment | Commercial and industrial | Loss
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	1
Prior	1,356	1,271
Total	1,356	1,272
Current | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
Year 1	1,374,603	2,835,460
Year 2	2,240,402	977,224
Year 3	679,211	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	4,294,216	3,812,684
Current | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
Year 1	5	49,721
Year 2	49,346	58,353
Year 3	56,510	31,465
Year 4	30,442	21,683
Year 5	21,358	4,546
Prior	34,430	33,248
Total	192,091	199,016
Current | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
Year 1	80,331	151,725
Year 2	124,585	38,076
Year 3	29,849	0
Year 4	0	2,543
Year 5	2,502	0
Prior	0	0
Total	237,267	192,344
Past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	15,994	5,776
Past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	1,168	4,031
Past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	12,676	102
Past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	2,150	1,643
30-59 days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
Year 1	3,279	11,149
Year 2	17,474	9,867
Year 3	9,013	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	29,766	21,016
30-59 days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	0	0
30-59 days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
Year 1	0	1,017
Year 2	35	703
Year 3	19	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	54	1,720
30-59 days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	2,784	3,172
30-59 days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	485	3,172
30-59 days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	2,115	0
30-59 days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	184	0
60-89 days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
Year 1	1,865	7,785
Year 2	14,153	8,633
Year 3	7,933	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	23,951	16,418
60-89 days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	254
Total	0	254
60-89 days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
Year 1	0	235
Year 2	51	147
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	51	382
60-89 days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	358	102
60-89 days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	0	0
60-89 days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	0	102
60-89 days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	358	0
90 or more days past due | Consumer Portfolio Segment | Unsecured personal
Term Loans and Leases by Origination Year
Year 1	1,213	6,813
Year 2	13,852	9,442
Year 3	8,332	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	23,397	16,255
90 or more days past due | Consumer Portfolio Segment | Residential mortgages
Term Loans and Leases by Origination Year
Year 1	0	0
Year 2	0	0
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	165	331
Total	165	331
90 or more days past due | Consumer Portfolio Segment | Secured consumer
Term Loans and Leases by Origination Year
Year 1	0	116
Year 2	0	72
Year 3	0	0
Year 4	0	0
Year 5	0	0
Prior	0	0
Total	0	188
90 or more days past due | Commercial Portfolio Segment
Term Loans and Leases by Origination Year
Total	12,852	2,502
90 or more days past due | Commercial Portfolio Segment | Equipment finance
Term Loans and Leases by Origination Year
Total	683	859
90 or more days past due | Commercial Portfolio Segment | Commercial real estate
Term Loans and Leases by Origination Year
Total	10,561	0
90 or more days past due | Commercial Portfolio Segment | Commercial and industrial
Term Loans and Leases by Origination Year
Total	$ 1,608	$ 1,643