Goodwill and Other Intangible Assets

A summary of changes in the Company’s goodwill by reportable segment is as follows (in thousands):



	December 31, 2017		Acquisitions		Acquisition Accounting Adjustments		Foreign Currency			December 31, 2018
Segment
North America	$	3,084,123	$	16,184	$	4,036	$	(16,468	)	$	3,087,875
International	1,631,700		—		20		(177,521		)	1,454,199
	$	4,715,823	$	16,184	$	4,056	$	(193,989	)	$	4,542,074



	December 31, 2016		Acquisitions		Dispositions			Acquisition Accounting Adjustments		Foreign Currency		December 31, 2017
Segment
North America	$	2,640,409	$	534,777	$	(92,046	)	$	—	$	983	$	3,084,123
International	1,554,741		21,325		—			3,752		51,882		1,631,700
	$	4,195,150	$	556,102	$	(92,046	)	$	3,752	$	52,865	$	4,715,823

At December 31, 2018 and 2017, approximately $882.3 million and $988.0 million of the Company’s goodwill is deductible for tax purposes, respectively. Acquisition accounting adjustments recorded in 2018 and 2017 are a result of the Company completing its acquisition accounting and working capital adjustments for certain prior year acquisitions.

Other intangible assets consisted of the following at December 31 (in thousands):



		2018							2017
	Weighted- Avg Useful Life (Years)	Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amount
Customer and vendor agreements	17.1	$	2,625,270	$	(776,383	)	$	1,848,887	$	2,698,428	$	(605,347	)	$	2,093,081
Trade names and trademarks—indefinite lived	N/A	479,555		—			479,555		499,587		—			499,587
Trade names and trademarks—other	13.8	2,957		(2,501		)	456		2,986		(2,207		)	779
Software	6.0	212,733		(152,416		)	60,317		219,019		(116,654		)	102,365
Non-compete agreements	4.2	47,009		(28,314		)	18,695		48,221		(19,076		)	29,145
Total other intangibles		$	3,367,524	$	(959,614	)	$	2,407,910	$	3,468,241	$	(743,284	)	$	2,724,957

Changes in foreign exchange rates resulted in a $117.4 million decrease to the carrying values of other intangible assets in the year ended December 31, 2018. Changes in foreign exchange rates resulted in a $24.2 million increase to the carrying values of other intangible assets in the year ended December 31, 2017. Amortization expense related to intangible assets for the years ended December 31, 2018, 2017 and 2016 was $216.3 million, $211.8 million and $161.6 million, respectively.

The future estimated amortization of intangibles at December 31, 2018 is as follows (in thousands):



2019	$	198,491
2020	179,005
2021	173,111
2022	160,403
2023	154,375
Thereafter	1,062,970