Intangible Assets

12 Months Ended

Dec. 31, 2019

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets

Note 10. Intangible Assets

The cost and accumulated amortization of intangible assets at December 31, 2019 and December 31, 2018 were as follows:

	December 31, 2019						December 31, 2018
	Carrying Amount		Accumulated Amortization		Net		Carrying Amount		Accumulated Amortization		Net
Patents, trademarks and technology	$	27	$	10	$	17	$	18	$	9	$	9
Other intangibles	14		10		4		14		7		7
Total	$	41	$	20	$	21	$	32	$	16	$	16

Amortization expense was $4 million, $3 million and $3 million for the years ended December 31, 2019, December 31, 2018 and December 31, 2017, respectively.

Our estimated future amortization expense for intangible assets over the next five years is as follows:

Year ending December 31,	Amount
2020	$	4
2021	5
2022	4
2023	4
2024	1