Lines of Credit - Composition of Partnership's Aggregate Bank Lines of Credit (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Line Of Credit Facility [Line Items]
Line of credit facility	$ 890	$ 890
2022 Credit Facility [Member]
Line Of Credit Facility [Line Items]
Line of credit facility	500	0
2018 Credit Facility [Member]
Line Of Credit Facility [Line Items]
Line of credit facility	0	500
Uncommitted Secured Credit Facilities [Member]
Line Of Credit Facility [Line Items]
Line of credit facility	$ 390	$ 390