Intangible assets and goodwill

12 Months Ended

Dec. 31, 2019

Intangible assets and goodwill

Intangible assets and goodwill

9.  INTANGIBLE ASSETS AND GOODWILL

	December 31, 2019						December 31, 2018
	Gross carrying value		Accumulated amortization		Net carrying value		Gross carrying value		Accumulated amortization		Net carrying value
Customer relationships	$	615	$	(102)	$	513	$	615	$	(58)	$	557
Backlog		330		(217)		113		330		(120)		210
Technologies		320		(144)		176		323		(83)		240
Software		213		(83)		130		159		(50)		109
Image library		80		(48)		32		80		(32)		48
Trade names and other		37		(10)		27		37		(5)		32
Non-compete agreements		—		—		—		20		(12)		8
Intangible assets	$	1,595	$	(604)	$	991	$	1,564	$	(360)	$	1,204

Amortization expense related to intangible assets was $269 million, $289 million and $97 million for the years ended December 31, 2019, 2018 and 2017, respectively. The decrease in expense for the year ended December 31, 2019 compared to 2018 was primarily due to impairments of intangible assets in the second half of 2018. The increase in expense for the year ended December 31, 2018 compared to 2017 was primarily due to the inclusion of a full year of amortization expense related to the additions of intangible assets from the acquisition of DigitalGlobe, as compared to approximately one quarter of amortization expense in 2017.

The estimated annual amortization expense related to finite-lived intangible assets as of December 31, 2019, is as follows:

	Year Ended December 31,
		2020		2021		2022		2023		2024		2025 and thereafter
Amortization expense	$	246	$	181	$	140	$	56	$	49	$	319

Goodwill balances for each reporting segment are as follows:

Goodwill is as follows:
	Earth Intelligence		Space Infrastructure		Total
Balance as of December 31, 2017
Goodwill	$	1,600	$	17	$	1,617
Accumulated impairment losses		—		—		—
		1,600		17		1,617
Impairment losses		(142)		(17)		(159)
Disposal of immaterial subsidiary		(3)		—		(3)
Balance as of December 31, 2018
Goodwill		1,597		17		1,614
Accumulated impairment losses		(142)		(17)		(159)
		1,455		—		1,455
Balance as of December 31, 2019
Goodwill		1,597		17		1,614
Accumulated impairment losses		(142)		(17)		(159)
	$	1,455	$	—	$	1,455