Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 2,257,017	$ 1,601,232
Accounts receivable (less accumulated provision for doubtful accounts: $3,619 at June 30, 2016 and $3,018 at December 31, 2015)	170,268	176,957
Derivative instruments, at fair value	136,591	417,397
Prepaid expenses and other	50,013	55,433
Total current assets	2,613,889	2,251,019
Property, plant and equipment	16,439,684	15,635,549
Less: accumulated depreciation and depletion	4,597,653	4,163,528
Net property, plant and equipment	11,842,031	11,472,021
Investment in nonconsolidated entity	135,949	77,025
Other assets	191,317	176,107
Total assets	14,783,186	13,976,172
Current liabilities:
Credit facility borrowings	0	299,000
Accounts payable	251,654	291,550
Derivative instruments, at fair value	110,960	23,434
Other current liabilities	164,663	181,835
Total current liabilities	527,277	795,819
Long-term debt	2,795,620	2,793,343
Deferred income taxes	1,807,522	1,972,170
Other liabilities and credits	395,314	386,798
Total liabilities	5,525,733	5,948,130
Stockholders’ equity:
Common stock, no par value, authorized 320,000 shares, shares issued: 177,897 at June 30, 2016 and 158,347 at December 31, 2015	3,402,840	2,153,280
Treasury stock, shares at cost: 5,150 at June 30, 2016 (including 226 held in rabbi trust) and 5,793 at December 31, 2015 (including 292 held in rabbi trust)	(92,478)	(104,079)
Retained earnings	2,719,427	2,982,212
Accumulated other comprehensive income	27,921	46,378
Total common stockholders’ equity	6,057,710	5,077,791
Noncontrolling interests in consolidated subsidiaries	3,199,743	2,950,251
Total equity	9,257,453	8,028,042
Total liabilities and equity	$ 14,783,186	$ 13,976,172

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

Name:	us-gaap_AccountsPayableCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.