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	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 321	$ 332	$ 507
Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	62	8	21
Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	2	18
Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	68	116	183
Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	70	63	55
Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	121	143	230
Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	2	19
Federal Education Loans [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	1
Federal Education Loans [Member] | Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	2	18
Federal Education Loans [Member] | Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Federal Education Loans [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Federal Education Loans [Member] | Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Federal Education Loans [Member] | Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	321	330	488
Business Processing [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	62	8	20
Business Processing [Member] | Guarantor Agencies [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Business Processing [Member] | Other Institutions [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Business Processing [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	68	116	183
Business Processing [Member] | Tolling Authorities [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	70	63	55
Business Processing [Member] | Hospitals and Other Healthcare Providers [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	121	143	230
Federal Education Loan Asset Recovery Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	2	19
Federal Education Loan Asset Recovery Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	2	19
Federal Education Loan Asset Recovery Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Government Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	200	187	258
Government Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Government Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	200	187	258
Healthcare Services [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	121	143	230
Healthcare Services [Member] | Federal Education Loans [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	0	0	0
Healthcare Services [Member] | Business Processing [Member]
Disaggregation Of Revenue [Line Items]
Total Revenue	$ 121	$ 143	$ 230