CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2016		Jun. 30, 2015
Operating Activities
Net loss		$ (195,872)		$ (88,275)
Adjustments to reconcile net loss to net cash provided by continuing operations activities:
(Income) loss from discontinued operations		(708)		2,819
Depreciation, depletion and amortization		541,388		884,417
Impairment of assets		95,088
Amortization of deferred major repair costs		3,798		3,404
Dry hole costs		14,270		99,023
Amortization of undeveloped leases		25,419		45,825
Accretion of asset retirement obligations		24,471		23,519
Deferred and noncurrent income tax benefits		(316,201)		(194,240)
Pretax gains from disposition of assets		(3,831)		(154,123)
Net (increase) decrease in noncash operating working capital		(86,793)	[1]	107,171
Other operating activities, net		12,349		(14,329)
Net cash provided by continuing operations activities		113,378		715,211
Investing Activities
Property additions and dry hole costs		(604,587)		(1,433,615)
Proceeds from sales of property, plant and equipment		1,153,325		423,106
Purchase of investment securities	[2]	(651,218)		(629,763)
Proceeds from maturity of investment securities	[2]	701,378		663,343
Other investing activities, net		(7,640)		(20,568)
Net cash provided (required) by investing activities		591,258		(997,497)
Financing Activities
Borrowings of debt				823,000
Repayments of debt		(600,000)		(450,000)
Capital lease obligation payments		(5,172)		(4,703)
Purchase of treasury stock				(250,000)
Withholding tax on stock-based incentive awards		(1,138)		(8,976)
Cash dividends paid		(120,535)		(124,581)
Other financing activities, net				(152)
Net cash required by financing activities		(726,845)		(15,412)
Cash Flows from Discontinued Operations
Operating activities		5,185		(85,445)
Investing activities				5,322
Changes in cash included in current assets held for sale		(5,185)		89,226
Net increase in cash and cash equivalents of discontinued operations				9,103
Effect of exchange rate changes on cash and cash equivalents		6,509		4,555
Net decrease in cash and cash equivalents		(15,700)		(284,040)
Cash and cash equivalents at January 1		283,183		1,193,308
Cash and cash equivalents at June 30		$ 267,483		$ 909,268

[1] 2016 balance includes payments for deepwater rig contract exit of $261.8 million.

[2] Investments are Canadian government securities with maturities greater than 90 days at the date of acquisition.