Goodwill and Other Intangible Assets

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



	December 31, 2018		Acquisition Accounting Adjustments		Foreign Currency			March 31, 2019
Segment
North America	$	3,087,875	$	2,711	$	4,574		$	3,095,160
International	1,454,199		—		(260		)	1,453,939
	$	4,542,074	$	2,711	$	4,314		$	4,549,099

As of March 31, 2019 and December 31, 2018, other intangible assets consisted of the following (in thousands):



		March 31, 2019							December 31, 2018
	Weighted- Avg Useful Lives (Years)	Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amounts		Accumulated Amortization			Net Carrying Amount
Customer and vendor relationships	17.1	$	2,620,473	$	(818,268	)	$	1,802,205	$	2,625,270	$	(776,383	)	$	1,848,887
Trade names and trademarks—indefinite lived	N/A	479,421		—			479,421		479,555		—			479,555
Trade names and trademarks—other	14.3	4,959		(2,577		)	2,382		2,957		(2,501		)	456
Software	5.9	213,601		(159,491		)	54,110		212,733		(152,416		)	60,317
Non-compete agreements	4.1	47,971		(30,450		)	17,521		47,009		(28,314		)	18,695
Total other intangibles		$	3,366,425	$	(1,010,786	)	$	2,355,639	$	3,367,524	$	(959,614	)	$	2,407,910

Changes in foreign exchange rates resulted in a $4.3 million increase to the carrying values of other intangible assets in the three months ended March 31, 2019. Amortization expense related to intangible assets for the three months ended March 31, 2019 and 2018 was $51.2 million and $57.8 million, respectively.