INTANGIBLES

The change in the carrying amount of goodwill by segment for the three months ended March 31, 2019 is as follows:



In thousands	Freight Segment			Transit Segment			Total
Balance at December 31, 2018	$	713,391		$	1,683,153		$	2,396,544
Additions	5,783,358			—			5,783,358
Foreign currency impact	(15,315		)	(22,114		)	(37,429		)
Balance at March 31, 2019	$	6,481,434		$	1,661,039		$	8,142,473

As of March 31, 2019 and December 31, 2018, the Company’s trade names had a net carrying amount of $624.6 million and $582.8 million, respectively. The Company believes these intangibles have indefinite lives, with the exception of the GET trade name, to which the company has assigned a useful life of 5 years.

Intangible assets of the Company, other than goodwill and trade names, consist of the following:



In thousands	March 31, 2019		December 31, 2018
Intellectual property, patents, non-compete and other intangibles, net of accumulated
amortization of $51,127 and $42,446	$	2,697,919	$	15,328
Customer relationships, net of accumulated amortization
of $168,774 and $158,533	1,041,551		531,761
Total	$	3,739,470	$	547,089

The weighted average remaining useful life of intellectual property, customer relationships and other intangibles were 10 years, 18 years and 13 years, respectively. Amortization expense for intangible assets was $27.4 million for the three months ended March 31, 2019, and $10.4 million for the three months ended March 31, 2018, respectively.

Amortization expense for the five succeeding years is estimated to be as follows:



Remainder of 2019	$	191,746
2020	254,053
2021	253,908
2022	253,596
2023	253,258