Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 23,153	$ 28,441
Accounts receivable, net of allowance for doubtful accounts of $1,320 and $1,195 at December 31, 2017 and March 31, 2018, respectively	26,692	34,896
Accrued revenue	279,923	300,122
Derivative instruments	459,892	460,685
Other current assets	10,374	8,943
Total current assets	800,034	833,087
Natural gas properties, at cost (successful efforts method):
Unproved properties	2,265,727	2,266,673
Proved properties	11,471,428	11,096,462
Water handling and treatment systems	974,389	946,670
Gathering systems and facilities	2,132,803	2,050,490
Other property and equipment	59,499	57,429
Property and equipment, gross	16,903,846	16,417,724
Less accumulated depletion, depreciation, and amortization	(3,410,098)	(3,182,171)
Property and equipment, net	13,493,748	13,235,553
Derivative instruments	760,562	841,257
Investments in unconsolidated affiliates	321,468	303,302
Other assets	47,037	48,291
Total assets	15,422,849	15,261,490
Current liabilities:
Accounts payable	73,221	62,982
Accrued liabilities	422,617	443,225
Revenue distributions payable	237,907	209,617
Derivative instruments	41,907	28,476
Other current liabilities	14,201	17,796
Total current liabilities	789,853	762,096
Long-term liabilities:
Long-term debt	4,876,706	4,800,090
Deferred income tax liability	788,765	779,645
Derivative instruments		207
Other liabilities	46,427	43,316
Total liabilities	6,501,751	6,385,354
Commitments and contingencies (notes 13 and 14)
Equity:
Common stock, $0.01 par value; authorized - 1,000,000 shares; 316,379 shares and 316,524 shares issued and outstanding at December 31, 2017 and March 31, 2018, respectively	3,165	3,164
Additional paid-in capital	6,588,082	6,570,952
Accumulated earnings	1,589,898	1,575,065
Total stockholders' equity	8,181,145	8,149,181
Noncontrolling interest in consolidated subsidiary	739,953	726,955
Total equity	8,921,098	8,876,136
Total liabilities and equity	$ 15,422,849	$ 15,261,490