3. Securitization Trust Debt (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Dec. 31, 2019
"Securitization trust debt," and components of debt
Receivables Pledged at end of period	[1]	$ 2,228,966
Initial Principal		5,491,419
Outstanding Principal		$ 2,103,710	$ 2,109,766
CPS 2014-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	December 2021
Receivables Pledged at end of period	[1]	$ 0
Initial Principal		273,000
Outstanding Principal		$ 0	19,758
Weighted Average Contractual Interest Rate
CPS 2014-D [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	March 2022
Receivables Pledged at end of period	[1]	$ 20,403
Initial Principal		267,500
Outstanding Principal		$ 19,476	23,755
Weighted Average Contractual Interest Rate		5.72%
CPS 2015-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	June 2022
Receivables Pledged at end of period	[1]	$ 23,427
Initial Principal		245,000
Outstanding Principal		$ 21,623	26,713
Weighted Average Contractual Interest Rate		5.62%
CPS 2015-B [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	September 2022
Receivables Pledged at end of period	[1]	$ 30,831
Initial Principal		250,000
Outstanding Principal		$ 31,032	36,338
Weighted Average Contractual Interest Rate		5.25%
CPS 2015-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	December 2022
Receivables Pledged at end of period	[1]	$ 45,935
Initial Principal		300,000
Outstanding Principal		$ 46,354	53,579
Weighted Average Contractual Interest Rate		5.95%
CPS 2016-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	March 2023
Receivables Pledged at end of period	[1]	$ 60,013
Initial Principal		329,460
Outstanding Principal		$ 62,489	71,599
Weighted Average Contractual Interest Rate		6.33%
CPS 2016-B [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	June 2023
Receivables Pledged at end of period	[1]	$ 73,496
Initial Principal		332,690
Outstanding Principal		$ 72,256	82,667
Weighted Average Contractual Interest Rate		6.71%
CPS 2016-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	September 2023
Receivables Pledged at end of period	[1]	$ 75,038
Initial Principal		318,500
Outstanding Principal		$ 73,378	83,696
Weighted Average Contractual Interest Rate		6.86%
CPS 2016-D [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	April 2024
Receivables Pledged at end of period	[1]	$ 59,088
Initial Principal		206,325
Outstanding Principal		$ 56,965	65,021
Weighted Average Contractual Interest Rate		5.00%
CPS 2017-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	April 2024
Receivables Pledged at end of period	[1]	$ 64,901
Initial Principal		206,320
Outstanding Principal		$ 62,536	71,450
Weighted Average Contractual Interest Rate		5.03%
CPS 2017-B [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	December 2023
Receivables Pledged at end of period	[1]	$ 79,576
Initial Principal		225,170
Outstanding Principal		$ 66,160	76,201
Weighted Average Contractual Interest Rate		4.32%
CPS 2017-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	September 2024
Receivables Pledged at end of period	[1]	$ 82,008
Initial Principal		224,825
Outstanding Principal		$ 70,376	80,315
Weighted Average Contractual Interest Rate		4.25%
CPS 2017-D [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	June 2024
Receivables Pledged at end of period	[1]	$ 83,976
Initial Principal		196,300
Outstanding Principal		$ 74,019	83,801
Weighted Average Contractual Interest Rate		3.87%
CPS 2018-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	March 2025
Receivables Pledged at end of period	[1]	$ 90,570
Initial Principal		190,000
Outstanding Principal		$ 80,840	91,258
Weighted Average Contractual Interest Rate		3.71%
CPS 2018-B [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	December 2024
Receivables Pledged at end of period	[1]	$ 105,665
Initial Principal		201,823
Outstanding Principal		$ 98,424	111,188
Weighted Average Contractual Interest Rate		4.13%
CPS 2018-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	September 2025
Receivables Pledged at end of period	[1]	$ 124,843
Initial Principal		230,275
Outstanding Principal		$ 114,360	130,064
Weighted Average Contractual Interest Rate		4.25%
CPS 2018-D [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	June 2025
Receivables Pledged at end of period	[1]	$ 146,617
Initial Principal		233,730
Outstanding Principal		$ 131,630	149,470
Weighted Average Contractual Interest Rate		4.21%
CPS 2019-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	March 2026
Receivables Pledged at end of period	[1]	$ 181,893
Initial Principal		254,400
Outstanding Principal		$ 166,520	186,900
Weighted Average Contractual Interest Rate		4.04%
CPS 2019-B [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	June 2026
Receivables Pledged at end of period	[1]	$ 175,677
Initial Principal		228,275
Outstanding Principal		$ 166,846	184,308
Weighted Average Contractual Interest Rate		3.66%
CPS 2019-C [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	September 2026
Receivables Pledged at end of period	[1]	$ 204,061
Initial Principal		243,513
Outstanding Principal		$ 196,387	216,650
Weighted Average Contractual Interest Rate		3.06%
CPS 2019-D [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	December 2026
Receivables Pledged at end of period	[1]	$ 252,186
Initial Principal		274,313
Outstanding Principal		$ 243,816	265,035
Weighted Average Contractual Interest Rate		2.64%
CPS 2020-A [Member]
"Securitization trust debt," and components of debt
Final Scheduled Payment Date	[2]	March 2027
Receivables Pledged at end of period	[1]	$ 248,762
Initial Principal		260,000
Outstanding Principal		$ 248,223	$ 0
Weighted Average Contractual Interest Rate		2.62%

[1] Includes repossessed assets that are included in Other assets on our Unaudited Condensed Consolidated Balance Sheet.

[2] The Final Scheduled Payment Date represents final legal maturity of the securitization trust debt. Securitization trust debt is expected to become due and to be paid prior to those dates, based on amortization of the finance receivables pledged to the trusts. Expected payments, which will depend on the performance of such receivables, as to which there can be no assurance, are $609.0 million in 2020, $627.2 million in 2021, $428.3 million in 2022, $308.8 million in 2023, $69.9 million in 2024, $48.6 million in 2025.