5. INTANGIBLES

The change in the carrying amount of goodwill by segment for the six months ended June 30, 2013 is as follows:

In thousands	Freight Segment
Balance at December 31, 2012	$	397,184		$	268,838		$	666,022
Acquisition		60,115			-			60,115
Adjustment to preliminary purchase allocation		(43	)		912			869
Foreign currency impact		(7,340	)		(4,712	)		(12,052	)
Balance at June 30, 2013	$	449,916		$	265,038		$	714,954

As of June 30, 2013 and December 31, 2012, the Company’s trademarks had a net carrying amount of $138.5 million and $131.3 million, respectively, and the Company believes these intangibles have an indefinite life.

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

In thousands	June 30, 2013		December 31, 2012
Patents and other, net of accumulated amortization of $36,121 and $35,556	$	12,250	$	11,835
Customer relationships, net of accumulated amortization of $37,571 and $31,572		179,059		165,160
Total	$	191,309	$	176,995

The weighted average remaining useful life of patents, customer relationships and intellectual property were six years, 16 years and 16 years, respectively. Amortization expense for intangible assets was $5.2 million and $8.8 million for the three and six months ended June 30, 2013, respectively, and $3.3 million and $6.3 million for the three and six months ended June 30, 2012, respectively.

Amortization expense for the five succeeding years is as follows (in thousands):

Remainder of 2013	$	8,035
2014		15,295
2015		14,259
2016		14,106
2017		12,584