6. Intangible Assets

The changes in the carrying amount of goodwill and intangible assets for the Company between January 1, 2014 and March 31, 2014 are as follows:


(in $ millions)	January 1, 2014		Additions		Retirements		Foreign Exchange		March 31, 2014
Non-Amortizable Assets:
Goodwill		986		—		—		—		986
Trademarks and tradenames		314		—		—		—		314
Other Intangible Assets:
Acquired intangible assets		1,129		—		—		—		1,129
Accumulated amortization		(610)		(19)		—		—		(629)

Acquired intangible assets, net		519		(19)		—		—		500

Customer loyalty payments		306		43		(28)		—		321
Accumulated amortization		(154)		(18)		28		—		(144)

Customer loyalty payments, net		152		25		—		—		177

Other intangible assets, net		671		6		—		—		677

The changes in the carrying amount of goodwill and intangible assets for the Company between January 1, 2013 and March 31, 2013 are as follows:


(in $ millions)	January 1, 2013		Additions		Retirements		Foreign Exchange		March 31, 2013
Non-Amortizable Assets:
Goodwill		986		—		—		—		986
Trademarks and tradenames		314		—		—		—		314
Other Intangible Assets:
Acquired intangible assets		1,129		—		—		—		1,129
Accumulated amortization		(530)		(20)		—		—		(550)

Acquired intangible assets, net		599		(20)		—		—		579

Customer loyalty payments		274		12		(47)		(1)		238
Accumulated amortization		(156)		(14)		47		—		(123)

Customer loyalty payments, net		118		(2)		—		(1)		115

Other intangible assets, net		717		(22)		—		(1)		694

The Company paid cash of $26 million and $12 million for customer loyalty payments during the three months ended March 31, 2014 and 2013, respectively. Further, as of March 31, 2014 and December 31, 2013, the Company had balances payable of $52 million and $35 million, respectively, for customer loyalty payments (see Note 8).

Amortization expense for acquired intangible assets, which consists of customer relationships, was $19 million and $20 million for the three months ended March 31, 2014 and 2013, respectively, 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 $18 million and $14 million for the three months ended March 31, 2014 and 2013, 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 intangible assets and customer loyalty payments balances to be:


	Twelve Months Ending March 31,
(in $ millions)	Acquired Intangible Assets		Customer Loyalty Payments
2015		73		61
2016		62		43
2017		45		31
2018		41		25
2019		41		15