Fair Value of Financial Instruments - Summary of Reconciliation of Fair Value of Contingent Consideration Obligations (Detail) $ in Millions	3 Months Ended
Mar. 31, 2022 USD ($) Arrangement
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Abstract]
Balances at beginning of period	$ 4
Issuances	0
Balance at end of period	$ 4
Number of open contingent consideration arrangements at the end of period \| Arrangement	2
Maximum potential payout at end of period	$ 3

Business combination contingent consideration arrangements maximum potential payout.

No definition available.

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Namespace Prefix:	apg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents number of such arrangements.

+ References

No definition available.

+ Details

Name:	apg_BusinessCombinationContingentConsiderationArrangementsNumberOfOpenArrangements
Namespace Prefix:	apg_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant