Intangibles

Definite Life Intangibles

The components of amortizable intangible assets are as follows at December 31:



		2016					2015
	Weighted	Gross					Gross
	Average	Carrying		Accumulated			Carrying		Accumulated
(in millions)	Life (years)	Amount		Amortization			Amount		Amortization
Customer related	12	$	197.1	$	(197.1	)	$	197.0	$	(183.5	)

Amortization expense for intangible assets recognized on a straight line basis was $13.5 million, $18.2 million and $18.3 million for the years ended December 31, 2016, 2015 and 2014, respectively. The definite-lived intangible assets are fully amortized in 2016.

Indefinite Life Intangibles

The following table shows the changes in the carrying amount of our indefinite lived tradenames attributable to each applicable segment:



(in millions)	YRC Freight			Regional Transportation		Total
Balances at December 31, 2013	$	10.6		$	18.7	$	29.3
Change in foreign currency exchange rates	(0.8		)	—		(0.8		)
Balances at December 31, 2014	9.8			18.7		28.5
Change in foreign currency exchange rates	(1.6		)	—		(1.6		)
Balances at December 31, 2015	8.2			18.7		26.9
Change in foreign currency exchange rates	0.3			—		0.3
Balances at December 31, 2016	$	8.5		$	18.7	$	27.2

Intangible assets with indefinite lives, which consist of our tradenames, are not subject to amortization, but are subjected to an impairment test at least annually or more frequently if a triggering event occurs. The impairment test for tradenames consists of a comparison of the fair value of the tradename with its carrying amount. An impairment loss is recognized for the amount by which the carrying amount exceeds the fair value of the asset. In making this assessment, we utilized the relief from royalty method, an income approach (a level 3 fair value measurement), which includes assumptions as to future revenue, applicable royalty rate and cost of capital, among others.