Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure Of Property Plant And Equipment [Abstract]

Summary of Property, Plant and Equipment

	December 31
	2017		2018
	NT$		NT$
	(In Millions)
Carrying amount
Land	$	104,079	$	103,972
Land improvements		302		263
Buildings		45,895		44,784
Computer equipment		2,374		2,115
Telecommunications equipment		114,900		116,322
Transportation equipment		321		231
Miscellaneous equipment		2,310		2,582
Construction in progress and equipment to be accepted		18,527		18,645
	$	288,708	$	288,914

	Land			Land Improvements			Buildings			Computer Equipment			Telecommuni- cations Equipment			Transportation Equipment			Miscellaneous Equipment			Construction in Progress and Equipment to be Accepted			Total
	NT$			NT$			NT$			NT$			NT$			NT$			NT$			NT$			NT$
	(In Millions)
Cost
Balance on    January 1, 2016	$	102,747		$	1,575		$	67,790		$	14,996		$	705,372		$	3,815		$	8,737		$	20,402		$	925,434
Additions		791			—			36			42			171			1			255			23,295			24,591
Disposal		(2	)		(6	)		(35	)		(1,546	)		(11,542	)		(54	)		(625	)		—			(13,810	)
Effect of foreign    exchange    differences		—			—			—			(3	)		(35	)		—			(4	)		—			(42	)
Others		336			12			(53	)		806			21,726			104			580			(23,556	)		(45	)
Balance on    December 31, 2016	$	103,872		$	1,581		$	67,738		$	14,295		$	715,692		$	3,866		$	8,943		$	20,141		$	936,128
Accumulated    depreciation    and impairment
Balance on    January 1, 2016	$	—		$	(1,203	)	$	(24,421	)	$	(11,715	)	$	(582,205	)	$	(2,750	)	$	(6,741	)	$	—		$	(629,035	)
Depreciation    expenses		—			(51	)		(1,269	)		(1,332	)		(25,280	)		(529	)		(626	)		—			(29,087	)
Disposal		—			6			34			1,529			11,512			54			583			—			13,718
Impairment losses		—			—			—			—			(596	)		—			—			—			(596	)
Effect of foreign    exchange    differences		—			—			—			1			7			—			4			—			12
Others		—			—			65			(65	)		65			(12	)		(23	)		—			30
Balance on    December 31, 2016	$	—		$	(1,248	)	$	(25,591	)	$	(11,582	)	$	(596,497	)	$	(3,237	)	$	(6,803	)	$	—		$	(644,958	)
Cost
Balance on    January 1, 2017	$	103,872		$	1,581		$	67,738		$	14,295		$	715,692		$	3,866		$	8,943		$	20,141		$	936,128
Additions		—			—			30			78			193			1			193			25,574			26,069
Disposal		(158	)		(5	)		(108	)		(974	)		(13,739	)		(62	)		(402	)		—			(15,448	)
Effect of foreign    exchange    differences		—			—			—			(1	)		(172	)		—			(3	)		—			(176	)
Others		365			19			5,034			764			20,080			29			784			(27,188	)		(113	)
Balance on    December 31, 2017	$	104,079		$	1,595		$	72,694		$	14,162		$	722,054		$	3,834		$	9,515		$	18,527		$	946,460

(Continued)

	Land			Land Improvements			Buildings			Computer Equipment			Telecommuni- cations Equipment			Transportation Equipment			Miscellaneous Equipment			Construction in Progress and Equipment to be Accepted			Total
	NT$			NT$			NT$			NT$			NT$			NT$			NT$			NT$			NT$
	(In Millions)
Accumulated    depreciation    and impairment
Balance on    January 1, 2017	$	—		$	(1,248	)	$	(25,591	)	$	(11,582	)	$	(596,497	)	$	(3,237	)	$	(6,803	)	$	—		$	(644,958	)
Depreciation    expenses		—			(50	)		(1,402	)		(1,192	)		(24,492	)		(330	)		(677	)		—			(28,143	)
Disposal		—			4			47			967			13,712			63			389			—			15,182
Effect of foreign    exchange    differences		—			—			—			—			45			—			2			—			47
Others		—			1			147			19			78			(9	)		(116	)		—			120
Balance on    December 31, 2017	$	—		$	(1,293	)	$	(26,799	)	$	(11,788	)	$	(607,154	)	$	(3,513	)	$	(7,205	)	$	—		$	(657,752	)
Cost
Balance on    January 1, 2018	$	104,079		$	1,595		$	72,694		$	14,162		$	722,054		$	3,834		$	9,515		$	18,527		$	946,460
Additions		—			—			21			52			159			—			334			27,413			27,979
Disposal		(71	)		—			—			(643	)		(31,984	)		(29	)		(623	)		—			(33,350	)
Effect of foreign    exchange    differences		—			—			—			—			60			—			—			—			60
Others		(36	)		6			196			687			25,459			77			648			(27,295	)		(258	)
Balance on    December 31, 2018	$	103,972		$	1,601		$	72,911		$	14,258		$	715,748		$	3,882		$	9,874		$	18,645		$	940,891
Accumulated    depreciation    and impairment
Balance on    January 1, 2018	$	—		$	(1,293	)	$	(26,799	)	$	(11,788	)	$	(607,154	)	$	(3,513	)	$	(7,205	)	$	—		$	(657,752	)
Depreciation    expenses		—			(45	)		(1,356	)		(983	)		(24,236	)		(162	)		(679	)		—			(27,461	)
Disposal		—			—			—			632			31,952			29			615			—			33,228
Effect of foreign    exchange    differences		—			—			—			—			(20	)		—			—			—			(20	)
Others		—			—			28			(4	)		32			(5	)		(23	)		—			28
Balance on    December 31, 2018	$	—		$	(1,338	)	$	(28,127	)	$	(12,143	)	$	(599,426	)	$	(3,651	)	$	(7,292	)	$	—		$	(651,977	)

(Concluded)

Disclosure Of Property Plant And Equipment Estimated Useful Life Explanatory

Depreciation expense is computed using the straight-line method over the following estimated service lives:

Land improvements	8-30 years
Buildings
Main buildings	35-60 years
Other building facilities	3-20 years
Computer equipment	2-8 years
Telecommunications equipment
Telecommunication circuits	2-30 years
Telecommunication machinery and    antennas equipment	2-30 years
Transportation equipment	3-10 years
Miscellaneous equipment
Leasehold improvements	1-6 years
Mechanical and air conditioner equipment	3-16 years
Others	1-10 years