7 Identified Intangible Assets

Intangible assets, net of accumulated amortization and impairments of $965 million and $1,171 million as of December 31, 2012 and 2011 respectively were composed of the following:


	December 31, 2012					December 31, 2011
	Gross		Accumulated amortization and impairments			Gross		Accumulated amortization and impairments
Marketing-related		18		(16	)		18		(16	)
Customer-related		427		(177	)		411		(143	)
Technology-based		2,053		(1,383	)		2,044		(1,156	)

Other intangible assets		2,498		(1,576	)		2,473		(1,315	)
Software		113		(70	)		63		(50	)

Identified intangible assets		2,611		(1,646	)		2,536		(1,365	)

The estimated amortization expense for these identified intangible assets for each of the five succeeding years is:


2013			232
2014			153
2015			132
2016			127
2017			113

All intangible assets, excluding goodwill, are subject to amortization and have no assumed residual value.

The expected weighted average remaining life of identified intangibles is 6 years as of December 31, 2012.

The estimated amortization expense for software as of December 31, 2012 for each of the five succeeding years is:


2013			21
2014			20
2015			2
2016			—
2017			—

The expected weighted average remaining lifetime of software is 2 years as of December 31, 2012.