6. Intangible Assets

The changes in the carrying amount of goodwill and other intangible assets for the Company between January 1, 2013 and September 30, 2013 are as follows:


(in $ millions)	January 1, 2013		Additions		Retirements		Foreign Exchange		September 30, 2013
Non-Amortizable Assets:
Goodwill		986		—		—		—		986
Trademarks and tradenames		314		—		—		—		314
Other Intangible Assets:
Acquired customer relationships		1,129		—		—		—		1,129
Accumulated amortization		(530)		(61)		—		—		(591)

Acquired customer relationships, net		599		(61)		—		—		538

Customer loyalty payments		274		67		(56)		—		285
Accumulated amortization		(156)		(45)		56		—		(145)

Customer loyalty payments, net		118		22		—		—		140

Other intangible assets, net		717		(39)		—		—		678

The changes in the carrying amount of goodwill and other intangible assets for the Company between January 1, 2012 and September 30, 2012 are as follows:


(in $ millions)	January 1, 2012		Additions		Retirements		Foreign Exchange		September 30, 2012
Non-Amortizable Assets:
Goodwill		986		—		—		—		986
Trademarks and tradenames		314		—		—		—		314
Other Intangible Assets:
Acquired customer relationships		1,129		—		—		—		1,129
Accumulated amortization		(448)		(61)		—		—		(509)

Acquired customer relationships, net		681		(61)		—		—		620

Customer loyalty payments		269		38		(28)		1		280
Accumulated amortization		(140)		(48)		28		—		(160)

Customer loyalty payments, net		129		(10)		—		1		120

Other intangible assets, net		810		(71)		—		1		740

The Company paid cash of $60 million and $38 million for customer loyalty payments during the nine months ended September 30, 2013 and 2012, respectively. Further, as of September 30, 2013 and December 31, 2012, the Company had a balance payable of $22 million and $15 million, respectively, for customer loyalty payments (see Note 8).

Customer loyalty payments are payments made to travel agents or travel providers with an objective of increasing the number of travel bookings using the Company’s GDS and to improve the travel agents’ or travel providers’ loyalty, which are instrumented through agreements with a term over a year. Under the contractual terms, the travel agent or travel provider commits to achieve certain economic objectives for the Company. Such costs are specifically identifiable to individual contracts with travel agents or travel providers, which have determinable contractual lives. Due to the contractual nature of the payments, the Company believes that such assets are more appropriately classified as internally developed identifiable intangible assets and, as a result, the Company has presented them within intangible assets with conforming changes to prior periods. As of December 31 2012, the Company included $50 million and $68 million as development advances within other current assets and other non-current assets, respectively, which have been re-classed as other intangible assets to conform to current period presentation.

Amortization expense for acquired customer relationships was $61 million for each of the nine months ended September 30, 2013 and 2012 and is included as a component of depreciation and amortization on the Company’s consolidated condensed statements of operations.

Amortization expense for customer loyalty payments was $45 million and $48 million for the nine months ended September 30, 2013 and 2012, respectively, and is included within revenue or cost of revenue in the Company’s consolidated condensed statements of operations.

The Company expects amortization expense relating to acquired customer relationships and customer loyalty payments to be:


	Twelve Months Ending September 30,
(in $ millions)	Acquired Customer Relationships		Customer Loyalty Payments
2014		77		53
2015		70		39
2016		54		21
2017		44		13
2018		41		6