INTANGIBLE ASSETS AND GOODWILL

The Company's intangible assets at June 30, 2018 and December 31, 2017 consisted of the following (in thousands):



	June 30, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Amortization Period	Weighted- Average Useful Life
Supply and distribution agreements	$	1,084,719	$	(382,281	)	$	702,438	$	1,056,660	$	(355,000	)	$	701,660	3 - 20 years	16 years

Technology	171,698		(114,680		)	57,018		137,288		(104,478		)	32,810		1 - 7 years	5 years

Patents	1,623		(1,623		)	—		1,623		(1,623		)	—		15 years	15 years

Internet domain names	41,112		(29,330		)	11,782		42,265		(28,802		)	13,463		5 - 20 years	8 years

Trade names	1,786,387		(395,009		)	1,391,378		1,779,076		(350,447		)	1,428,629		4-20 years	19 years

Non-compete agreements	21,900		(21,750		)	150		21,900		(21,639		)	261		3-4 years	3 years
Total intangible assets	$	3,107,439	$	(944,673	)	$	2,162,766	$	3,038,812	$	(861,989	)	$	2,176,823

Intangible assets are amortized on a straight-line basis. Amortization expense was approximately $45.7 million and $92.3 million for the three and six months ended June 30, 2018, respectively, and $41.2 million and $84.2 million for the three and six months ended June 30, 2017, respectively.

The amortization expense for intangible assets for the remainder of 2018 and the annual expense for the next five years and thereafter is expected to be as follows (in thousands):



Remainder of 2018	$	85,753
2019	168,793
2020	160,962
2021	154,945
2022	152,191
2023	150,181
Thereafter	1,289,941
	$	2,162,766

A roll-forward of goodwill for the six months ended June 30, 2018 consisted of the following (in thousands):



Balance at December 31, 2017	$	2,737,671
Acquisition	131,583
Currency translation adjustments	(18,858		)
Balance at June 30, 2018	$	2,850,396

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 June 30, 2018.

Acquisition

In April 2018, the Company paid $139.4 million, net of cash acquired, and issued shares of the Company's common stock in the amount of $110.4 million in connection with an acquisition of a local activities and experiences booking software provider. In respect of the shares issued, as shown in the supplemental disclosure in the Unaudited Consolidated Statement of Cash Flows, $59.7 million relates to purchase price consideration and $50.7 million relates to shares restricted for trading purposes until the required post-acquisition services are completed by certain employees. At June 30, 2018, the Company's Unaudited Consolidated Balance Sheet includes approximately $17 million in "Prepaid expenses and other current assets" and approximately $31 million in "Other assets" related to this deferred compensation charge associated with these restricted shares.