Intangible Assets

3 Months Ended

Mar. 31, 2015

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets

7. Intangible Assets

The following table summarizes the components of our intangible assets at the dates indicated:

	March 31, 2015						December 31, 2014
	Gross Carrying Amount		Accumulated Amortization		Carrying Value		Gross Carrying Amount		Accumulated Amortization		Carrying Value
Refinery Services:
Customer relationships	$	94,654	$	82,981	$	11,673	$	94,654	$	81,880	$	12,774
Licensing agreements	38,678		29,661		9,017		38,678		28,983		9,695
Segment total	133,332		112,642		20,690		133,332		110,863		22,469
Supply & Logistics:
Customer relationships	35,430		30,601		4,829		35,430		30,228		5,202
Intangibles associated with lease	13,260		3,631		9,629		13,260		3,512		9,748
Segment total	48,690		34,232		14,458		48,690		33,740		14,950
Marine contract intangibles	32,000		2,083		29,917		32,000		833		31,167
Other	23,821		8,968		14,853		22,797		8,452		14,345
Total	$	237,843	$	157,925	$	79,918	$	236,819	$	153,888	$	82,931

Our amortization of intangible assets for the periods presented was as follows:

	Three Months Ended March 31,
	2015		2014
Amortization of intangible assets	$	4,037	$	3,145

We estimate that our amortization expense for the next five years will be as follows:

Remainder of	2015	$	13,922
	2016	$	15,613
	2017	$	14,450
	2018	$	12,334
	2019	$	8,021