Share Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Share Based Compensation Tables [Abstract]

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Text Block]

4. SHARE BASED COMPENSATION:
Valuation and Expense Information
			Three Months				Nine Months
			Ended September 30,				Ended September 30,
			2016		2015		2016		2015
	Total cost of share-based payment plans	$	1,706	$	3,963	$	5,756	$	8,247
	Amounts capitalized in oil and gas properties
	and equipment	$	442	$	1,283	$	1,789	$	2,738
	Amounts charged against income, before
	income tax benefit	$	1,264	$	2,680	$	3,967	$	5,509
	Amount of related income tax benefit
	recognized in income before valuation allowance	$	503	$	1,120	$	1,579	$	2,303

Stock Option Activity TextBlock

		Weighted
	Number of	Average
	Options	Exercise Price
	(000's)	(US Dollars)
Balance, December 31, 2014	690	$	25.68	to	$	98.87
Expired or forfeited	(171)	$	25.68	to	$	75.18
Balance, December 31, 2015	519	$	49.05	to	$	98.87
Expired or forfeited	(109)	$	50.48	to	$	75.18
Balance, September 30, 2016	410	$	49.05	to	$	98.87

Valuation Assumptions

Valuation Assumptions
The Company estimates the fair value of the market condition related to the LTIP awards on the date of grant using a Monte Carlo simulation with the following assumptions:
	2015 LTIP	2014 LTIP
Volatility of common stock	40.1%	39.0%
Average volatility of peer companies	46.5%	n/a
Average correlation coefficient of peer companies	0.454	n/a
Risk-free interest rate	1.02%	0.66%