Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents		$ 28,441
Accounts receivable, net of allowance for doubtful accounts of $1,320 at December 31, 2017 and $1,195 at September 30, 2018, respectively	$ 46,604	34,896
Accrued revenue	354,010	300,122
Derivative instruments	493,354	460,685
Other current assets	12,664	8,943
Total current assets	906,632	833,087
Natural gas properties, at cost (successful efforts method):
Unproved properties	1,928,990	2,266,673
Proved properties	12,306,198	11,096,462
Water handling and treatment systems	993,285	946,670
Gathering systems and facilities	2,384,041	2,050,490
Other property and equipment	62,739	57,429
Property and equipment, gross	17,675,253	16,417,724
Less accumulated depletion, depreciation, and amortization	(3,890,834)	(3,182,171)
Property and equipment, net	13,784,419	13,235,553
Derivative instruments	672,768	841,257
Investments in unconsolidated affiliates	392,893	303,302
Other assets	45,823	48,291
Total assets	15,802,535	15,261,490
Current liabilities:
Accounts payable	91,940	62,982
Accrued liabilities	457,216	443,225
Revenue distributions payable	245,832	209,617
Derivative instruments	10,456	28,476
Other current liabilities	8,427	17,796
Total current liabilities	813,871	762,096
Long-term liabilities:
Long-term debt	5,487,004	4,800,090
Deferred income tax liability	782,145	779,645
Derivative instruments		207
Other liabilities	48,363	43,316
Total liabilities	7,131,383	6,385,354
Commitments and contingencies (notes 12 and 13)
Equity:
Preferred stock, $0.01 par value; authorized - 50,000 shares; none issued
Common stock, $0.01 par value; authorized - 1,000,000 shares; 316,379 shares and 317,086 shares issued and outstanding at December 31, 2017 and September 30, 2018, respectively	3,171	3,164
Additional paid-in capital	6,611,348	6,570,952
Accumulated earnings	1,299,094	1,575,065
Total stockholders' equity	7,913,613	8,149,181
Noncontrolling interest in consolidated subsidiary	757,539	726,955
Total equity	8,671,152	8,876,136
Total liabilities and equity	$ 15,802,535	$ 15,261,490