CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 18,719		$ 22,938
Accounts receivable	542,037		464,045
Inventories	38,846		37,745
Derivative assets	11,444		70,871
Other current assets	72,055		48,576
Total current assets	683,101		644,175
Property and Equipment:
Natural gas and oil properties, using the full cost method, including $878.7 million in 2014 and $956.5 million in 2013 excluded from amortization	13,773,604		13,293,841
Gathering systems	1,344,607		1,306,074
Other	709,856		702,544
Less: Accumulated depreciation, depletion and amortization	(8,225,394)		(8,005,836)
Total property and equipment, net	7,602,673		7,296,623
Other long-term assets	137,390		106,928
TOTAL ASSETS	8,423,164		8,047,726
Current liabilities:
Accounts payable	642,744		507,468
Taxes payable	55,156		68,019
Interest payable	14,109		33,485
Current deferred income taxes			24,353
Other current liabilities	123,146		54,686
Total current liabilities	835,155		688,011
Long-term debt	1,827,426		1,950,096
Deferred income taxes	1,694,196		1,532,329
Pension and other postretirement liabilities	16,413		15,823
Other long-term liabilities	249,534		239,437
Total long-term liabilities	3,787,569		3,737,685
Commitments and contingencies (Note 11)
Equity:
Common stock, $0.01 par value; authorized 1,250,000,000 shares; issued 353,083,763 shares in 2014 and 352,938,584 in 2013	3,531		3,529
Additional paid-in capital	985,396		970,524
Retained earnings	2,846,843		2,652,653
Accumulated other comprehensive loss	(34,967)	[1]	(4,342)	[1]
Common stock in treasury, 10,608 shares in 2014 and 9,924 in 2013	(363)		(334)
Total equity	3,800,440		3,622,030
TOTAL LIABILITIES AND EQUITY	$ 8,423,164		$ 8,047,726

[1] All amounts are net-of-tax.