Revenue from Contracts with Customers Accounted for in Accordance with ASC 606 - Summary of Disaggregation of Revenue from Contracts with Customers Accounted Under ASC 606 (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 85	$ 79	$ 240	$ 261
Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	20	2	43	6
Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	1
State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	17	27	52	95
Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	20	18	54	48
Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	28	32	91	111
Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	1
Federal Education Loans [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Federal Education Loans [Member] | Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	1
Federal Education Loans [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Federal Education Loans [Member] | Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Federal Education Loans [Member] | Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	85	79	240	260
Business Processing [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	20	2	43	6
Business Processing [Member] | Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Business Processing [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	17	27	52	95
Business Processing [Member] | Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	20	18	54	48
Business Processing [Member] | Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	28	32	91	111
Federal Education Loan Asset Recovery Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	1
Federal Education Loan Asset Recovery Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	1
Federal Education Loan Asset Recovery Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Government Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	57	47	149	149
Government Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Government Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	57	47	149	149
Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	28	32	91	111
Healthcare Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0	0
Healthcare Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 28	$ 32	$ 91	$ 111