Finance Receivables - Recorded Investment in Retail Finance Receivables, by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Loss [Line Items]
Total financing receivables	$ 6,911,300	$ 6,833,944	$ 7,572,947	$ 7,411,816	$ 7,157,557
United States
Financing Receivable, Allowance for Credit Loss [Line Items]
Total financing receivables	6,703,453
Canada
Financing Receivable, Allowance for Credit Loss [Line Items]
Total financing receivables	207,847
Retail
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	2,949,726	2,467,348
2020	1,518,657	1,730,885
2019	1,006,457	1,082,250
2018	575,460	591,597
2017	278,817	309,427
2016 & Prior	164,402	162,688
Total financing receivables	6,493,519	6,344,195	$ 6,416,428	$ 6,328,201	$ 6,140,600
Retail | United States
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	2,878,709	2,392,143
2020	1,471,124	1,665,438
2019	968,569	1,041,840
2018	554,299	569,957
2017	269,964	300,604
2016 & Prior	160,628	158,287
Total financing receivables	6,303,293	6,128,269
Retail | United States | Super prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	1,010,636	822,631
2020	484,479	575,977
2019	316,390	355,529
2018	171,763	165,436
2017	65,753	71,360
2016 & Prior	27,424	29,181
Total financing receivables	2,076,445	2,020,114
Retail | United States | Prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	1,391,385	1,133,637
2020	712,858	794,058
2019	470,177	508,713
2018	277,206	293,358
2017	142,288	156,688
2016 & Prior	82,169	77,046
Total financing receivables	3,076,083	2,963,500
Retail | United States | Sub-prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	476,688	435,875
2020	273,787	295,403
2019	182,002	177,598
2018	105,330	111,163
2017	61,923	72,556
2016 & Prior	51,035	52,060
Total financing receivables	1,150,765	1,144,655
Retail | Canada
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	71,017	75,205
2020	47,533	65,447
2019	37,888	40,410
2018	21,161	21,640
2017	8,853	8,823
2016 & Prior	3,774	4,401
Total financing receivables	190,226	215,926
Retail | Canada | Super prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	51,779	53,465
2020	32,724	48,692
2019	27,073	28,581
2018	13,984	13,818
2017	4,619	5,018
2016 & Prior	1,614	2,011
Total financing receivables	131,793	151,585
Retail | Canada | Prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	16,882	18,568
2020	12,675	14,257
2019	9,244	10,269
2018	6,230	6,727
2017	3,628	3,198
2016 & Prior	1,779	2,025
Total financing receivables	50,438	55,044
Retail | Canada | Sub-prime
Financing Receivable, Allowance for Credit Loss [Line Items]
2021	2,356	3,172
2020	2,134	2,498
2019	1,571	1,560
2018	947	1,095
2017	606	607
2016 & Prior	381	365
Total financing receivables	$ 7,995	$ 9,297