v3.26.1
Loans Receivable (Summary of Changes in Loans Receivable and Allowance for Credit Losses) (Details) - USD ($)
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Mar. 31, 2025
Dec. 31, 2024
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable $ (7,959,200,000) $ (8,001,900,000) $ (7,959,200,000) $ (8,001,900,000) $ (7,956,400,000) $ (7,909,200,000) $ (7,978,200,000) $ (7,850,300,000)
Finance Charges Revenue (546,200,000) (540,700,000) (1,084,600,000) (1,067,400,000)        
Provision for Credit Losses (159,200,000) (172,600,000) (298,800,000) (334,500,000)        
New Consumer Loan Assignments [1] 999,200,000 998,000,000.0 2,067,800,000 2,110,700,000        
Proceeds from Collection of Loans Receivable [2] (1,430,400,000) (1,409,400,000) (2,901,300,000) (2,830,500,000)        
Accelerated Payments of Dealer Holdback 12,500,000 14,600,000 25,000,000.0 27,800,000        
Payments of Dealer Holdback 31,000,000.0 48,700,000 65,600,000 103,500,000        
Loans And Leases Receivable Transfers [3] 0 0 0 0        
Write-offs 0 0 0 0        
Recoveries [4] 0 0 0 0        
Deferral of Loan Origination Costs 3,500,000 3,700,000 7,100,000 7,200,000        
Dealer Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (5,650,000,000) (5,785,100,000) (5,650,000,000) (5,785,100,000) (5,705,400,000) (5,701,700,000) (5,799,700,000) (5,676,500,000)
Finance Charges Revenue (358,200,000) (359,300,000) (713,100,000) (708,600,000)        
Provision for Credit Losses (79,700,000) (102,000,000.0) (151,400,000) (206,700,000)        
New Consumer Loan Assignments [1] 651,200,000 682,000,000.0 1,390,800,000 1,517,800,000        
Proceeds from Collection of Loans Receivable [2] (1,005,300,000) (993,400,000) (2,042,900,000) (1,995,100,000)        
Accelerated Payments of Dealer Holdback 12,500,000 14,600,000 25,000,000.0 27,800,000        
Payments of Dealer Holdback 31,000,000.0 48,700,000 65,600,000 103,500,000        
Loans And Leases Receivable Transfers [3] (26,800,000) (27,500,000) (59,000,000.0) (54,500,000)        
Write-offs 0 0 0 0        
Recoveries [4] 0 0 0 0        
Deferral of Loan Origination Costs 3,500,000 3,700,000 7,100,000 7,200,000        
Purchased Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (2,309,200,000) (2,216,800,000) (2,309,200,000) (2,216,800,000) (2,251,000,000) (2,207,500,000) (2,178,500,000) (2,173,800,000)
Finance Charges Revenue (188,000,000.0) (181,400,000) (371,500,000) (358,800,000)        
Provision for Credit Losses (79,500,000) (70,600,000) (147,400,000) (127,800,000)        
New Consumer Loan Assignments [1] 348,000,000.0 316,000,000.0 677,000,000.0 592,900,000        
Proceeds from Collection of Loans Receivable [2] (425,100,000) (416,000,000.0) (858,400,000) (835,400,000)        
Accelerated Payments of Dealer Holdback 0 0 0 0        
Payments of Dealer Holdback 0 0 0 0        
Loans And Leases Receivable Transfers [3] (26,800,000) (27,500,000) (59,000,000.0) (54,500,000)        
Write-offs 0 0 0 0        
Recoveries [4] 0 0 0 0        
Deferral of Loan Origination Costs 0 0 0 0        
Loans Receivable [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (11,608,700,000) (11,563,000,000) (11,608,700,000) (11,563,000,000) (11,578,500,000) (11,511,500,000) (11,476,700,000) (11,289,100,000)
Finance Charges Revenue (788,100,000) (772,300,000) (1,565,000,000) (1,524,700,000)        
Provision for Credit Losses 0 0 0 0        
New Consumer Loan Assignments [1] 999,200,000 998,000,000.0 2,067,800,000 2,110,700,000        
Proceeds from Collection of Loans Receivable [2] (1,430,400,000) (1,409,400,000) (2,901,300,000) (2,830,500,000)        
Accelerated Payments of Dealer Holdback 12,500,000 14,600,000 25,000,000.0 27,800,000        
Payments of Dealer Holdback 31,000,000.0 48,700,000 65,600,000 103,500,000        
Loans And Leases Receivable Transfers [3] 0 0 0 0        
Write-offs 376,500,000 343,500,000 736,800,000 672,900,000        
Recoveries [4] (2,800,000) (1,900,000) (4,800,000) (3,400,000)        
Deferral of Loan Origination Costs 3,500,000 3,700,000 7,100,000 7,200,000        
Loans Receivable [Member] | Dealer Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (8,787,500,000) (8,791,000,000) (8,787,500,000) (8,791,000,000) (8,824,200,000) (8,790,800,000) (8,734,100,000) (8,521,000,000)
Finance Charges Revenue (560,500,000) (548,100,000) (1,114,700,000) (1,079,300,000)        
Provision for Credit Losses 0 0 0 0        
New Consumer Loan Assignments [1] 651,200,000 682,000,000.0 1,390,800,000 1,517,800,000        
Proceeds from Collection of Loans Receivable [2] (1,005,300,000) (993,400,000) (2,042,900,000) (1,995,100,000)        
Accelerated Payments of Dealer Holdback 12,500,000 14,600,000 25,000,000.0 27,800,000        
Payments of Dealer Holdback 31,000,000.0 48,700,000 65,600,000 103,500,000        
Loans And Leases Receivable Transfers [3] (39,100,000) (39,600,000) (86,200,000) (80,000,000.0)        
Write-offs 251,600,000 207,600,000 478,500,000 391,200,000        
Recoveries [4] (600,000) (400,000) (1,100,000) (700,000)        
Deferral of Loan Origination Costs 3,500,000 3,700,000 7,100,000 7,200,000        
Loans Receivable [Member] | Purchased Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (2,821,200,000) (2,772,000,000) (2,821,200,000) (2,772,000,000) (2,754,300,000) (2,720,700,000) (2,742,600,000) (2,768,100,000)
Finance Charges Revenue (227,600,000) (224,200,000) (450,300,000) (445,400,000)        
Provision for Credit Losses 0 0 0 0        
New Consumer Loan Assignments [1] 348,000,000.0 316,000,000.0 677,000,000.0 592,900,000        
Proceeds from Collection of Loans Receivable [2] (425,100,000) (416,000,000.0) (858,400,000) (835,400,000)        
Accelerated Payments of Dealer Holdback 0 0 0 0        
Payments of Dealer Holdback 0 0 0 0        
Loans And Leases Receivable Transfers [3] (39,100,000) (39,600,000) (86,200,000) (80,000,000.0)        
Write-offs 124,900,000 135,900,000 258,300,000 281,700,000        
Recoveries [4] (2,200,000) (1,500,000) (3,700,000) (2,700,000)        
Deferral of Loan Origination Costs 0 0 0 0        
Allowance for Credit Losses [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (3,649,500,000) (3,561,100,000) (3,649,500,000) (3,561,100,000) (3,622,100,000) (3,602,300,000) (3,498,500,000) (3,438,800,000)
Finance Charges Revenue (241,900,000) (231,600,000) (480,400,000) (457,300,000)        
Provision for Credit Losses (159,200,000) (172,600,000) (298,800,000) (334,500,000)        
New Consumer Loan Assignments [1] 0 0 0 0        
Proceeds from Collection of Loans Receivable [2] 0 0 0 0        
Accelerated Payments of Dealer Holdback 0 0 0 0        
Payments of Dealer Holdback 0 0 0 0        
Loans And Leases Receivable Transfers [3] 0 0 0 0        
Write-offs 376,500,000 343,500,000 736,800,000 672,900,000        
Recoveries [4] (2,800,000) (1,900,000) (4,800,000) (3,400,000)        
Deferral of Loan Origination Costs 0 0 0 0        
Allowance for Credit Losses [Member] | Dealer Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (3,137,500,000) (3,005,900,000) (3,137,500,000) (3,005,900,000) (3,118,800,000) (3,089,100,000) (2,934,400,000) (2,844,500,000)
Finance Charges Revenue (202,300,000) (188,800,000) (401,600,000) (370,700,000)        
Provision for Credit Losses (79,700,000) (102,000,000.0) (151,400,000) (206,700,000)        
New Consumer Loan Assignments [1] 0 0 0 0        
Proceeds from Collection of Loans Receivable [2] 0 0 0 0        
Accelerated Payments of Dealer Holdback 0 0 0 0        
Payments of Dealer Holdback 0 0 0 0        
Loans And Leases Receivable Transfers [3] (12,300,000) (12,100,000) (27,200,000) (25,500,000)        
Write-offs 251,600,000 207,600,000 478,500,000 391,200,000        
Recoveries [4] (600,000) (400,000) (1,100,000) (700,000)        
Deferral of Loan Origination Costs 0 0 0 0        
Allowance for Credit Losses [Member] | Purchased Loans [Member]                
Loans and Leases Receivable, Net [Roll Forward]                
Loans Receivable (512,000,000.0) (555,200,000) (512,000,000.0) (555,200,000) $ (503,300,000) $ (513,200,000) $ (564,100,000) $ (594,300,000)
Finance Charges Revenue (39,600,000) (42,800,000) (78,800,000) (86,600,000)        
Provision for Credit Losses (79,500,000) (70,600,000) (147,400,000) (127,800,000)        
New Consumer Loan Assignments [1] 0 0 0 0        
Proceeds from Collection of Loans Receivable [2] 0 0 0 0        
Accelerated Payments of Dealer Holdback 0 0 0 0        
Payments of Dealer Holdback 0 0 0 0        
Loans And Leases Receivable Transfers [3] (12,300,000) (12,100,000) (27,200,000) (25,500,000)        
Write-offs 124,900,000 135,900,000 258,300,000 281,700,000        
Recoveries [4] (2,200,000) (1,500,000) (3,700,000) (2,700,000)        
Deferral of Loan Origination Costs $ 0 $ 0 $ 0 $ 0        
[1] The Dealer Loans amount represents advances paid to Dealers on Consumer Loans assigned under the Portfolio Program. The Purchased Loans amount represents one-time payments made to Dealers to purchase Consumer Loans assigned under the Purchase Program.
[2] Represents repayments that we collected on Consumer Loans assigned under our programs.
[3] Under the Portfolio Program, certain events may result in Dealers forfeiting their rights to Dealer Holdback. We transfer the Dealer’s outstanding Dealer Loan balance and related allowance for credit losses balance to Purchased Loans in the period this forfeiture occurs.
[4] The Dealer Loans amount represents net cash flows received (collections less any related Dealer Holdback payments) on Dealer Loans that were previously written off in full. The Purchased Loans amount represents collections received on Purchased Loans that were previously written off in full.