Intangible Assets

3 Months Ended

Mar. 31, 2017

Intangible Assets, Net (Excluding Goodwill) [Abstract]

Intangible Assets

Intangible Assets

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

	March 31, 2017						December 31, 2016
	Gross Carrying Amount		Accumulated Amortization		Carrying Value		Gross Carrying Amount		Accumulated Amortization		Carrying Value
Refinery Services:
Customer relationships	$	94,654	$	90,441	$	4,213	$	94,654	$	89,756	$	4,898
Licensing agreements	38,678		34,785		3,893		38,678		34,204		4,474
Segment total	133,332		125,226		8,106		133,332		123,960		9,372
Supply & Logistics:
Customer relationships	35,430		34,027		1,403		35,430		33,676		1,754
Intangibles associated with lease	13,260		4,578		8,682		13,260		4,459		8,801
Segment total	48,690		38,605		10,085		48,690		38,135		10,555
Marine contract intangibles	27,000		7,650		19,350		27,000		6,300		20,700
Offshore pipeline contract intangibles	158,101		13,868		144,233		158,101		11,788		146,313
Other	28,703		11,328		17,375		28,569		10,622		17,947
Total	$	395,826	$	196,677	$	199,149	$	395,692	$	190,805	$	204,887

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

	Three Months Ended March 31,
	2017		2016
Amortization of intangible assets	$	5,872	$	5,992

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

Remainder of	2017	$	17,733
	2018	$	21,502
	2019	$	17,167
	2020	$	16,249
	2021	$	10,622