Other Intangible Assets and Liabilities

Amortized intangible assets and liabilities were as follows (in millions):



	As of June 30, 2012				As of December 31, 2011
	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
Amortized intangible assets	$	2,013	$	746	$	2,013	$	593
Amortized intangible liabilities	$	2,056	$	701	$	2,056	$	560

Amortized intangible assets primarily consisted of internally developed software and franchise and customer assets. Amortized intangible liabilities primarily consisted of customer and shortline contracts which were in an unfavorable position at the date of Merger.

Amortized intangible assets and liabilities are amortized based on the estimated pattern in which the economic benefits are expected to be consumed or on a straight-line basis over their estimated economic lives.

Amortization of intangible assets and liabilities was as follows (in millions):



	Six Months Ended June 30,
	2012		2011
Amortization of intangible assets	$	153	$	157
Amortization of intangible liabilities	$	141	$	147

Amortization of intangible assets and liabilities for the next five years is expected to approximate the following (in millions):



	Amortization of intangible assets		Amortization of intangible liabilities
Remainder of 2012	$	153	$	141
2013	$	306	$	252
2014	$	306	$	179
2015	$	54	$	115
2016	$	31	$	101