Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 28,482	$ 35,729
Receivables:
Crude oil and natural gas sales	643,498	468,650
Affiliated parties	13,107	12,410
Joint interest and other, net	349,579	356,111
Derivative assets	3,616	18,389
Inventories	54,440	46,743
Deferred and prepaid taxes	44,337	365
Prepaid expenses and other	10,207	8,386
Total current assets	1,147,266	946,783
Net property and equipment, based on successful efforts method of accounting	10,721,272	8,105,269
Net debt issuance costs and other	72,644	55,726
Noncurrent derivative assets	0	32,231
Total assets	11,941,182	9,140,009
Current liabilities:
Accounts payable trade	885,289	687,310
Revenues and royalties payable	291,772	261,856
Payables to affiliated parties	5,436	6,069
Accrued liabilities and other	198,113	155,681
Derivative liabilities	90,535	12,999
Current portion of long-term debt	2,011	1,950
Total current liabilities	1,473,156	1,125,865
Long-term debt, net of current portion	4,713,821	3,537,771
Other noncurrent liabilities:
Deferred income tax liabilities	1,736,812	1,262,576
Asset retirement obligations, net of current portion	54,353	44,944
Noncurrent derivative liabilities	7,829	2,173
Other noncurrent liabilities	2,093	2,981
Total other noncurrent liabilities	1,801,087	1,312,674
Commitments and contingencies (Note 10)
Shareholders’ equity:
Preferred stock, $0.01 par value; 25,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.01 par value; 500,000,000 shares authorized; 185,658,659 shares issued and outstanding at December 31, 2013; 185,604,681 shares issued and outstanding at December 31, 2012	1,857	1,856
Additional paid-in capital	1,252,034	1,226,835
Retained earnings	2,699,227	1,935,008
Total shareholders’ equity	3,953,118	3,163,699
Total liabilities and shareholders’ equity	$ 11,941,182	$ 9,140,009