INTANGIBLE ASSETS AND GOODWILL

The Company's intangible assets at March 31, 2019 and December 31, 2018 consisted of the following (in millions):



	March 31, 2019							December 31, 2018
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Amortization Period
Supply and distribution agreements	$	1,095	$	(422	)	$	673	$	1,099	$	(408	)	$	691	3 - 20 years

Technology	173		(125		)	48		173		(121		)	52		1 - 7 years

Patents	2		(2		)	—		2		(2		)	—		15 years

Internet domain names	40		(30		)	10		41		(30		)	11		5 - 20 years

Trade names	1,810		(463		)	1,347		1,810		(439		)	1,371		4 - 20 years

Non-compete agreements	—		—			—		1		(1		)	—
Total intangible assets	$	3,120	$	(1,042	)	$	2,078	$	3,126	$	(1,001	)	$	2,125

Intangible assets are amortized on a straight-line basis. Amortization expense was $45 million and $47 million for the three months ended March 31, 2019 and 2018, respectively.

A substantial portion of the Company's intangibles and goodwill relates to the acquisitions of OpenTable in July 2014 and KAYAK in May 2013. There were no events or changes in circumstances to indicate a potential impairment to goodwill or intangible assets at March 31, 2019.

Acquisition

In November 2018, the Company paid $134 million, net of cash acquired, to complete the acquisition of HotelsCombined, a hotel meta-search company. The purchase price allocation has not been completed at March 31, 2019. The Company's Unaudited Consolidated Financial Statements include the accounts of this business starting at the acquisition date. Revenues and earnings of this business since the acquisition date and pro forma results of operations have not been presented separately as such financial information is not material to the Company's results of operations.