Fair Value Measurements (Fair Value of Note Payable and Long-Term Debt) (Detail) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	$ 50	$ 54
Total	885	1,099
6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 29	$ 34
Interest rate	6.90%	6.90%
6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 418	$ 501
Interest rate	6.92%	6.92%
6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 388	$ 510
Interest rate	6.125%	6.125%
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	$ 0	$ 0
Total	0	0
Level 1 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 1 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 1 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	50	54
Total	885	1,099
Level 2 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	29	34
Level 2 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	418	501
Level 2 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	388	510
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	0	0
Total	0	0
Level 3 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 3 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 3 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 0	$ 0