Other Intangibles (Notes)

12 Months Ended

Dec. 31, 2014

Other Intangible Assets Disclosure [Abstract]

Intangible Assets Disclosure [Text Block]

Other Intangible Assets

Our identifiable intangible assets are are as follows (in thousands):



	Useful			Accumulated
As of December 31, 2014	Life	Gross		Amortization			Net
Intangible assets subject to amortization:
Supply contracts (Gross)	11.5	$	12,227	$	(8,949	)	$	3,278
Intangible assets not subject to amortization:
Rights-of-way assets	Indefinite	8,071		—			8,071
Total		$	20,298	$	(8,949	)	$	11,349



	Useful			Accumulated
As of December 31, 2013	Life	Gross		Amortization			Net
Intangible assets subject to amortization:
Supply contracts (Gross)	11.5	$	12,227	$	(7,885	)	$	4,342
Intangible assets not subject to amortization:
Rights-of-way assets	Indefinite	8,032		—			8,032
Total		$	20,259	$	(7,885	)	$	12,374

Amortization of intangible assets was $1.1 million during each of the years ended December 31, 2014, 2013 and 2012 and is included in depreciation and amortization on the accompanying consolidated statements of income and comprehensive income. Amortization expense is estimated to be $1.1 million per year for the years ended 2015 through 2017, at which point our supply contracts will be fully amortized.