Summary of Significant Accounting Policies - Summary of Subsidiaries (Detail)						12 Months Ended
	Jul. 31, 2020	Oct. 09, 2019	Dec. 06, 2018	Nov. 28, 2018	Mar. 24, 2000	Dec. 31, 2021	Dec. 31, 2020
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership	1.40%	1.30%	1.70%	48.74%		38.45%	43.97%
Smart Communications, Inc. [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership					100.00%
Smart Communications, Inc. [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Cellular mobile services
Smart Communications, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Smart Broadband, Inc. and Subsidiary [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Internet broadband distribution services
Smart Broadband, Inc. and Subsidiary [Member] | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Primeworld Digital Systems, Inc. [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Internet broadband distribution services
Primeworld Digital Systems, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
I-Contacts Corporation [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Operations support servicing business
I-Contacts Corporation [Member] | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Far East Capital Limited | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Cayman Islands
Principal Business Activity						Cost effective offshore financing and    risk management activities for Smart
Far East Capital Limited | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Ph Communications Holdings Corporation | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Investment company
Ph Communications Holdings Corporation | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Connectivity Unlimited Resource Enterprise | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Cellular mobile services
Connectivity Unlimited Resource Enterprise | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Francom Holdings Inc | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Investment company
Francom Holdings Inc | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Chikka Holdings Limited And Subsidiaries | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						British Virgin Islands
Principal Business Activity						Content provider, mobile applications    development and services
Chikka Holdings Limited And Subsidiaries | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Wi Fun Inc | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Software developer and selling    of WiFi access equipment
Wi Fun Inc | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT Global, Inc. [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Cross-border digital platforms and other allied services
PLDT Global, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
ACeS Philippines Cellular Satellite Corporation [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Satellite information and messaging services
ACeS Philippines Cellular Satellite Corporation [Member] | Operating Segments [Member] | Direct [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						88.50%	88.50%
ACeS Philippines Cellular Satellite Corporation [Member] | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						11.50%	11.50%
Digitel Mobile Philippines, Inc. [Member] | Operating Segments [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Cellular mobile services
Digitel Mobile Philippines, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Wireless [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						99.60%	99.60%
PLDT Clark Telecom, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications services
PLDT Clark Telecom, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT Subic Telecom, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications services
PLDT Subic Telecom, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT Global Corporation and Subsidiaries [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						British Virgin Islands
Principal Business Activity						Telecommunications services
PLDT Global Corporation and Subsidiaries [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Smart-NTT Multimedia, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Data and network services
Smart-NTT Multimedia, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT-Philcom, Inc. and Subsidiaries [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications services
PLDT-Philcom, Inc. and Subsidiaries [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Talas Data Intelligence, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Business infrastructure and solutions;    intelligent data processing and    implementation services and data    analytics insight generation
Talas Data Intelligence, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
ePLDT, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Information and communications    infrastructure for internet-based    services, e-commerce, customer    relationship management and IT    related services
ePLDT, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
IP Converge Data Services, Inc. and Subsidiary [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Information and communications    infrastructure for internet-based    services, e-commerce, customer    relationship management and IT    related services
IP Converge Data Services, Inc. and Subsidiary [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Curo Teknika, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Managed IT outsourcing
Curo Teknika, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
ABM Global Solutions, Inc. and Subsidiaries [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Internet-based purchasing, IT    consulting and professional services
ABM Global Solutions, Inc. and Subsidiaries [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
ePDS, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Bills printing and other related    value-added services, or VAS
ePDS, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Net Games Inc [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Gaming support services
Net Games Inc [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						57.50%	57.50%
MVP Rewards Loyalty Solutions, Inc [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Full-services customer rewards and loyalty    programs
MVP Rewards Loyalty Solutions, Inc [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Digital Telecommunications Phils., Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications services
Digital Telecommunications Phils., Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						99.60%	99.60%
Digitel Information Technology Services, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Internet services
Digitel Information Technology Services, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						99.60%	99.60%
PLDT-Maratel, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications services
PLDT-Maratel, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						98.00%	98.00%
Bonifacio Communications Corporation [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Telecommunications, infrastructure and related    VAS
Bonifacio Communications Corporation [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						75.00%	75.00%
Pacific Global One Aviation Company, Inc. [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Air transportation business
Pacific Global One Aviation Company, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						65.30%	65.30%
Pilipinas Global Network Limited and Subsidiaries [Member] | Operating Segments [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						British Virgin Islands
Principal Business Activity						International distributor of Filipino    channels and content
Pilipinas Global Network Limited and Subsidiaries [Member] | Operating Segments [Member] | Direct [Member] | Fixed Line [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						64.60%	64.60%
PLDT Global Investments Holdings, Inc. [Member] | Operating Segments [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Investment company
PLDT Global Investments Holdings, Inc. [Member] | Operating Segments [Member] | Direct [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT Digital Investments Pte. Ltd. and Subsidiaries [Member] | Operating Segments [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Singapore
Principal Business Activity						Investment company
PLDT Digital Investments Pte. Ltd. and Subsidiaries [Member] | Operating Segments [Member] | Direct [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
Mabuhay Investments Corporation, or MIC [Member] | Operating Segments [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Investment company
Mabuhay Investments Corporation, or MIC [Member] | Operating Segments [Member] | Direct [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						67.00%	67.00%
PLDT Global Investments Corporation [Member] | Operating Segments [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						British Virgin Islands
Principal Business Activity						Investment company
PLDT Global Investments Corporation [Member] | Operating Segments [Member] | Indirect [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						100.00%	100.00%
PLDT Communications and Energy Ventures, Inc. [Member] | Operating Segments [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Place of Incorporation						Philippines
Principal Business Activity						Investment company
PLDT Communications and Energy Ventures, Inc. [Member] | Operating Segments [Member] | Indirect [Member] | Others [Member]
Disclosure Of Significant Investments In Subsidiaries [Line Items]
Percentage of Ownership						99.90%	99.90%