Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,958,157	$ 1,077,429
Accounts receivable (less accumulated provision for doubtful accounts: $3,658 at June 30, 2015 and $5,311 at December 31, 2014)	150,390	306,085
Derivative instruments, at fair value	349,152	458,460
Prepaid expenses and other	32,608	62,349
Total current assets	2,490,307	1,904,323
Equity in nonconsolidated investments	46,478	0
Property, plant and equipment	14,808,650	13,608,151
Less: accumulated depreciation and depletion	3,906,192	3,531,337
Net property, plant and equipment	10,902,458	10,076,814
Other assets	133,087	83,763
Total assets	13,572,330	12,064,900
Current liabilities:
Current portion of long-term debt	160,000	166,011
Short-term loans	312,000	0
Accounts payable	287,323	444,077
Derivative instruments, at fair value	43,696	22,942
Other current liabilities	228,304	200,449
Total current liabilities	1,031,323	833,479
Long-term debt	2,818,200	2,822,889
Deferred income taxes	1,801,490	1,750,870
Other liabilities and credits	276,076	284,599
Total liabilities	5,927,089	5,691,837
Stockholders’ equity:
Common stock, no par value, authorized 320,000 shares, shares issued: 175,347 at June 30, 2015 and 175,384 at December 31, 2014	2,351,616	1,895,632
Treasury stock, shares at cost: 22,943 at June 30, 2015 and 23,788 at December 31, 2014	(414,174)	(429,440)
Retained earnings	3,085,173	2,917,129
Accumulated other comprehensive income	116,638	199,494
Total common stockholders’ equity	5,139,253	4,582,815
Noncontrolling interests in consolidated subsidiaries	2,505,988	1,790,248
Total equity	7,645,241	6,373,063
Total liabilities and equity	$ 13,572,330	$ 12,064,900