Finance Receivables - Recorded Investment in Retail Finance Receivables, by Credit Quality Indicator (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Financing Receivable, Allowance for Credit Losses
Total	$ 8,286,383	$ 7,932,154	$ 7,880,231
Gross charge-offs for the three months ended March 31, 2024:
Total	81,368	68,008
Retail
Financing Receivable, Allowance for Credit Losses
Year 1	708,187	700,813	2,637,198
Year 2	2,414,038	2,765,558	2,043,433
Year 3	1,837,677	1,648,678	1,176,286
Year 4	1,041,701	786,931	526,884
Year 5	453,933	467,899	280,805
More than 5 years	343,974	338,224	154,093
Total	6,799,510	6,708,103	6,818,699
Gross charge-offs for the three months ended March 31, 2024:
Year 1	0	0	20,574
Year 2	22,005	23,740	103,391
Year 3	29,083	22,780	75,078
Year 4	16,498	10,365	31,368
Year 5	7,256	5,851	18,366
More than 5 years	6,526	5,272	15,138
Total	81,368	68,008	263,915
Retail | United States
Financing Receivable, Allowance for Credit Losses
Year 1	693,429	686,156	2,572,883
Year 2	2,356,399	2,704,482	1,998,720
Year 3	1,798,357	1,611,180	1,150,467
Year 4	1,019,696	764,166	512,436
Year 5	441,954	452,785	273,031
More than 5 years	335,771	329,020	150,461
Total	6,645,606	6,547,789	6,657,998
Gross charge-offs for the three months ended March 31, 2024:
Year 1	0	0	20,047
Year 2	21,760	23,440	102,387
Year 3	28,748	22,535	74,212
Year 4	16,286	10,215	30,896
Year 5	7,111	5,818	18,088
More than 5 years	6,363	5,100	14,655
Total	80,268	67,108	260,285
Retail | Canada
Financing Receivable, Allowance for Credit Losses
Year 1	14,758	14,657	64,315
Year 2	57,639	61,076	44,713
Year 3	39,320	37,498	25,819
Year 4	22,005	22,765	14,448
Year 5	11,979	15,114	7,774
More than 5 years	8,203	9,204	3,632
Total	153,904	160,314	160,701
Gross charge-offs for the three months ended March 31, 2024:
Year 1	0	0	527
Year 2	245	300	1,004
Year 3	335	245	866
Year 4	212	150	472
Year 5	145	33	278
More than 5 years	163	172	483
Total	1,100	900	3,630
Retail | Super prime | United States
Financing Receivable, Allowance for Credit Losses
Year 1	311,848	284,656	1,066,321
Year 2	963,226	1,007,543	729,339
Year 3	651,375	547,008	376,474
Year 4	328,904	240,495	151,004
Year 5	126,727	133,205	70,627
More than 5 years	73,138	72,247	27,013
Total	2,455,218	2,285,154	2,420,778
Retail | Super prime | Canada
Financing Receivable, Allowance for Credit Losses
Year 1	11,736	10,428	48,705
Year 2	43,504	44,213	31,733
Year 3	27,785	26,550	17,744
Year 4	15,068	15,250	9,241
Year 5	7,456	9,921	4,521
More than 5 years	4,063	4,668	1,524
Total	109,612	111,030	113,468
Retail | Prime | United States
Financing Receivable, Allowance for Credit Losses
Year 1	294,135	314,959	1,173,463
Year 2	1,087,821	1,317,733	993,417
Year 3	900,078	799,814	584,305
Year 4	522,250	378,539	259,995
Year 5	226,247	224,682	139,011
More than 5 years	173,807	170,944	78,880
Total	3,204,338	3,206,671	3,229,071
Retail | Prime | Canada
Financing Receivable, Allowance for Credit Losses
Year 1	2,566	3,650	13,764
Year 2	12,375	14,850	11,434
Year 3	10,180	9,711	7,336
Year 4	6,336	6,482	4,390
Year 5	3,779	4,439	2,728
More than 5 years	3,526	3,917	1,838
Total	38,762	43,049	41,490
Retail | Sub-prime | United States
Financing Receivable, Allowance for Credit Losses
Year 1	87,446	86,541	333,099
Year 2	305,352	379,206	275,964
Year 3	246,904	264,358	189,688
Year 4	168,542	145,132	101,437
Year 5	88,980	94,898	63,393
More than 5 years	88,826	85,829	44,568
Total	986,050	1,055,964	1,008,149
Retail | Sub-prime | Canada
Financing Receivable, Allowance for Credit Losses
Year 1	456	579	1,846
Year 2	1,760	2,013	1,546
Year 3	1,355	1,237	739
Year 4	601	1,033	817
Year 5	744	754	525
More than 5 years	614	619	270
Total	$ 5,530	$ 6,235	$ 5,743