Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Schedule of Finite-Lived Intangible Assets

The following table summarizes the carrying value of our CO₂ purchase contract intangible asset as of December 31, 2016 and 2015:

	December 31,
In thousands	2016			2015
Intangible asset value	$	34,341		$	34,341
Accumulated amortization	(8,203		)	(5,915		)
Net book value	$	26,138		$	28,426

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

As of December 31, 2016, our estimated amortization expense for our intangible asset subject to amortization over the next five years is as follows:

In thousands
2017	$	2,289
2018	2,289
2019	2,289
2020	2,289
2021	2,289

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

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

	Year Ended December 31,
In thousands	2016	2015	2014
Basic weighted average common shares outstanding	373,859	348,802	348,962
Potentially dilutive securities
Restricted stock, stock options, SARs and performance-based equity awards	—	—	2,205
Diluted weighted average common shares outstanding	373,859	348,802	351,167

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following securities could potentially dilute earnings per share in the future, but were excluded from the computation of diluted net income (loss) per share, as their effect would have been antidilutive:

	Year Ended December 31,
In thousands	2016	2015	2014
Stock options and SARs	6,427	9,619	4,775
Restricted stock and performance-based equity awards	5,816	3,867	417