Share Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

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
			Ended March 31,
			2013		2012
	Total cost of share-based payment plans	$	4,502	$	3,681
	Amounts capitalized in oil and gas properties
	and equipment	$	1,494	$	1,225
	Amounts charged against income, before
	income tax benefit	$	3,008	$	2,456
	Amount of related income tax benefit recognized
	in income before valuation allowance	$	1,238	$	1,011

Stock Option Activity TextBlock

		Weighted
	Number of	Average
	Options	Exercise Price
	(000's)	(US$)
Balance, December 31, 2011	1,459	$	16.97	to	$	98.87
Forfeited	(68)	$	25.08	to	$	75.18
Exercised	(34)	$	16.97	to	$	19.18
Balance, December 31, 2012	1,357	$	16.97	to	$	98.87
Forfeited	-	$	0.00	to	$	0.00
Exercised	-	$	0.00	to	$	0.00
Balance, March 31, 2013	1,357	$	16.97	to	$	98.87