Business Combinations - Additional Information (Detail) $ in Millions			3 Months Ended		12 Months Ended
	Jan. 03, 2022 USD ($)	Oct. 01, 2019	Mar. 31, 2022 USD ($) Country	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)
Cash payment			$ 2,875	$ 7
Maximum payout of contingent compensation			$ 22
Senior Notes [Member]
Line of credit facility, interest rate				4.75%
Contractual Backlog [Member]
Finite-Lived Intangible Asset, Useful Life	1 year
Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life	15 years		11 years 9 months 18 days		6 years 4 months 24 days
Trade names and Trademarks [Member]
Finite-Lived Intangible Asset, Useful Life	15 years
2022 Acquisitions [Member]
Total transaction costs			$ 24
2021 Acquisitions [Member]
Purchase price consideration transferred			111
Cash paid at closing			93
Cash payment			7
Business combination accrued consideration			18
Goodwill, expected tax deduction					$ 46
APi Acquisition [Member]
Contingent compensation					12	$ 15
Maximum payout of contingent compensation					57
Payout of accrued contingent compensation			15		12
Liability for deferred payments			14		$ 15
APi Acquisition [Member] | Minimum [Member]
Contingent compensation arrangements recognized period		3 years
Liability for deferred payments recognition period		12 months
APi Acquisition [Member] | Maximum [Member]
Contingent compensation arrangements recognized period		5 years
Liability for deferred payments recognition period		24 months
Chubb Limited Fire and Security Business [Member]
Cash paid at closing	$ 2,935
Other estimated adjustments	$ (36)
Line of credit facility, interest rate	4.75%
Total transaction costs	$ 43
Net revenues from acquisition			543
Operating income (loss) from acquisition			$ 10
Number of countries of significant business operations | Country			17
Number of countries expanding operations | Country			20
Chubb Limited Fire and Security Business [Member] | Safety Services [Member]
Provisional Goodwill	$ 1,225