Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Accounting Policies [Abstract]

Schedule of Finite-Lived Intangible Assets

The following table summarizes the carrying values of our intangible assets as of December 31, 2014 and 2013:

In thousands	Helium Production Rights			CO2 Purchase Contract			Total
December 31, 2014
Intangible asset value	$	55,266		$	34,341		$	89,607
Accumulated amortization	(15		)	(3,625		)	(3,640		)
Net book value as of December 31, 2014	$	55,251		$	30,716		$	85,967
December 31, 2013
Intangible asset value	$	55,266		$	33,931		$	89,197
Accumulated amortization	—			(1,319		)	(1,319		)
Net book value as of December 31, 2013	$	55,266		$	32,612		$	87,878

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

At December 31, 2014, our estimated amortization expense for our intangible assets subject to amortization over the next five years is as follows:

In thousands
2015	$	2,289
2016	2,488
2017	2,788
2018	2,858
2019	2,833

Weighted average shares used in basic and diluted net income per common share

The following is a reconciliation of the weighted average shares used in the basic and diluted net income per common share calculations for the periods indicated:

	Year Ended December 31,
In thousands	2014	2013	2012
Basic weighted average common shares outstanding	348,962	366,659	385,205
Potentially dilutive securities
Restricted stock, stock options, SARs and performance-based equity awards	2,205	3,218	3,733
Diluted weighted average common shares outstanding	351,167	369,877	388,938