Acquired Intangible Assets

6 Months Ended

Jun. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Acquired intangible assets were specifically identified when acquired, and are deemed to have finite lives. The gross carrying amount and accumulated amortization for the Company's acquired intangible assets were as follows:



		June 30, 2018					December 31, 2017
In millions	Amortization Life (in Years)	Gross Carrying Amount		Accumulated Amortization and Currency Translation Adjustments			Gross Carrying Amount		Accumulated Amortization and Currency Translation Adjustments
Acquired intangible assets
Intellectual property/developed technology	3 to 5	$	35	$	(16	)	$	43	$	(20	)

The gross carrying amount of acquired intangibles was reduced by certain intangible assets previously acquired that became fully amortized and were removed from the balance sheet.

The aggregate amortization expense (actual and estimated) for acquired intangible assets is as follows:



	Three Months Ended June 30				Six Months Ended June 30,
In millions	2018		2017		2018		2017
Amortization expense	$	2	$	1	$	4	$	3



	Actual		For the years ended (estimated)
In millions	2017		2018		2019		2020		2021		2022
Amortization expense	$	8	$	7	$	6	$	4	$	4	$	2