Derivative Instruments And Hedging Activities (Tables)

12 Months Ended

Dec. 31, 2011

Derivative Instruments And Hedging Activities [Abstract]

Derivatives Designated As Hedging Instruments

	As of December 31, 2011			As of December 31, 2010
	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Asset Derivatives:
Natural gas contracts	Other current assets	$	12,957	Other current assets	$	5,324
Oil contracts	Other current assets		8,567	Other current assets		—
Natural gas contracts	Other assets		857	Other assets		—
Interest rate swaps	Other assets		327	Other assets		—
		$	22,708		$	5,324

	As of December 31, 2011			As of December 31, 2010
	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Liability Derivatives:
Oil contracts	Accrued liabilities	$	886	Accrued liabilities	$	28,855
Interest rate swaps	Accrued liabilities		202	Accrued liabilities		1,751
Gas contracts	Other long-term liabilities		—	Other long-term liabilities		913
Oil contracts	Other long-term liabilities		1,711	Other long-term liabilities		—
Interest rate swaps	Other long-term liabilities		—	Other long-term liabilities		115
		$	2,799		$	31,634

Derivatives Not Designated As Hedging Instruments

	As of December 31, 2011			As of December 31, 2010
	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Asset Derivatives:
Foreign exchange forwards	Other current assets	$	55	Other current assets	$	148
Foreign exchange forwards	Other assets		—	Other assets		42
		$	55		$	190

	As of December 31, 2011			As of December 31, 2010
	Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
Liability Derivatives:
Foreign exchange forwards	Accrued liabilities	$	159	Accrued liabilities	$	—
		$	159		$	—

Impact Of Derivative Instruments On Accumulated Comprehensive Income (Loss)

	Gain (Loss) Recognized in OCI on Derivatives
		2011(1)		2010			2009
Oil and natural gas commodity contracts	$	28,749	$	(6,486	)	$	(19,092	)
Foreign exchange forwards		—		—			(538	)
Interest rate swaps		1,294		(1,213	)		712
	$	30,043	$	(7,699	)	$	(18,918	)

(1)   All unrealized gains (losses) related to our derivatives are expected to be reclassified into earnings by no later than December 31, 2014.  The last of our interest rate swaps will be settled in January 2014.  The last of our oil and natural gas commodity contracts will settle in December 2013.  Most of our unrealized gain (losses) in OCI at December 31, 2011 is expected to be reclassified to earnings in 2012, including $13.4 million for our oil and natural gas contracts and $(0.1) million related to our interest swap contracts.

Gain (Loss) Reclassified From Accumulated OCI Into Income

	Location of Gain (Loss) Reclassified from Accumulated OCI into Income		Gain (Loss) Reclassified from Accumulated OCI into Income
			Years Ended December 31,
			2011			2010			2009
Oil and  natural gas commodity contracts	Oil and Gas Revenues	$	(21,659	)	$	25,575		$	16,972
Interest rate swaps	Net interest expense		(2,010	)		(1,849	)		(1,096	)
		$	(23,669	)	$	23,726		$	15,876

Impact Of Non-Designated Derivative Instruments On Income Statement

	Location of Gain (Loss) Recognized in Income on Derivatives		Gain (Loss) Recognized in Income on Derivatives
			Years Ended December 31,
			2011		2010			2009
Natural gas contracts	Gain on oil and gas derivative contracts	$	—	$	1,088		$	89,485
Foreign exchange forwards	Other income (expense)		249		(2,560	)		3,279
Interest rate swaps	Other income (expense)		—		—			(468	)
		$	249	$	(1,472	)	$	92,296