Pension And Other Retirement Benefits - Summary of Pension Plan Assets by Category Based on Hierarchy of Fair Value Measurements (Detail) - Pension Plans - U.S. Plans - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 544	$ 528	$ 395
Percent of total assets	100.00%	100.00%
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 41	$ 39
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	434	421
Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	69	68
Cash and cash equivalent
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 4	$ 4
Percent of total assets	1.00%	1.00%
Cash and cash equivalent | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 4	$ 4
Total equity investments
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 185	$ 203
Percent of total assets	34.00%	38.00%
Total equity investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 185	$ 203
U.S. large-cap
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 135	$ 143
Percent of total assets	25.00%	27.00%
U.S. large-cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 135	$ 143
U.S. small and mid-cap
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 23	$ 28
Percent of total assets	4.00%	5.00%
U.S. small and mid-cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 23	$ 28
Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 27	$ 32
Percent of total assets	5.00%	6.00%
Emerging markets | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 27	$ 32
Total fixed-income investments
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 330	$ 297
Percent of total assets	61.00%	56.00%
Total fixed-income investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 41	$ 39
Total fixed-income investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	245	214
Total fixed-income investments | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	44	44
Emerging markets bond fund
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 30	$ 32
Percent of total assets	6.00%	6.00%
Emerging markets bond fund | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 30	$ 32
Intermediate-term investment grade U.S. government/ corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 245	$ 214
Percent of total assets	45.00%	41.00%
Intermediate-term investment grade U.S. government/ corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 245	$ 214
U.S. Treasury Inflation-Protected Securities (TIPs)
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 24	$ 23
Percent of total assets	4.00%	4.00%
U.S. Treasury Inflation-Protected Securities (TIPs) | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 24	$ 23
Convertible securities
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 17	$ 16
Percent of total assets	3.00%	3.00%
Convertible securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 17	$ 16
Private investment fund—high yield securities
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 14	$ 12
Percent of total assets	3.00%	2.00%
Private investment fund—high yield securities | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 14	$ 12
Other investment—private real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 25	$ 24
Percent of total assets	4.00%	5.00%
Other investment—private real estate fund | Measured using NAV practical expedient
Defined Benefit Plan Disclosure [Line Items]
Total assets	$ 25	$ 24