Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021		Dec. 31, 2020
Gain on divestiture of legacy asbestos-related assets and liabilities before income tax				$ 88.8
Deconsolidation Gain or Loss, Tax Amount				116.9
Deconsolidation. Gain / Loss, Amount				28.1
Asbestos Related Matters [Member]
Asbestos remeasurement				0.0	[1]	$ 135.9
Liability [Member] | Asbestos Related Matters [Member]
Asbestos remeasurement				0.0	[1]	155.7
Gross Asbestos Liability, current and noncurrent						$ 932.0
Asbestos Issue
Payments for Other Operating Activities				$ 398.0
Asbestos Related Matters [Member]
Asbestos Settlement Agreement Cash Proceeds			$ 66.4
Asbestos Related Costs (Benefit), Settlement Agreement	$ 52.1	$ 4.2	$ 52.5

[1] In 2020, we extended our projection to include pending claims and claims expected to be filed through 2052, which reflected the full time period over which we expected asbestos-related claims to be filed against InTelCo.