CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Operating Activities
Net income including noncontrolling interest		$ 72,769	$ 168,253	[1]
Adjustments to reconcile net income to net cash provided by continuing operations activities:
(Income) loss from discontinued operations		(49,846)	(77,672)	[1]
Depreciation, depletion and amortization		229,406	182,743	[1]
Previously suspended exploration costs (credits)		13,251	(5)	[1]
Amortization of undeveloped leases		8,045	13,168	[1]
Accretion of asset retirement obligations		9,340	6,372	[1]
Deferred income tax charge (benefit)		15,589	(147,716)	[1]
Pretax (gain) loss from sale of assets		(12)	339	[1]
Mark to market and revaluation of contingent consideration		13,530
Mark to market of crude contracts	[1]		14,350
Long-term non-cash compensation		22,388	14,057	[1]
Net (increase) decrease in noncash operating working capital		(98,505)	(3,553)	[1]
Other operating activities, net		(18,758)	(59,449)	[1]
Net cash provided by continuing operations activities		217,197	110,887	[1]
Investing Activities
Property additions and dry hole costs		(270,338)	(247,054)	[1]
Proceeds from sales of property, plant and equipment	[1]		260
Net cash required by investing activities		(270,338)	(246,794)	[1]
Financing Activities
Capital lease obligation payments		(160)
Withholding tax on stock-based incentive awards		(6,991)	(6,642)	[1]
Distribution to noncontrolling interest		(18,437)
Cash dividends paid		(43,398)	(43,258)	[1]
Net cash required by financing activities		(68,986)	(49,900)	[1]
Cash Flows from Discontinued Operations
Operating activities		123,469	167,386	[1]
Investing activities		(26,438)	(26,848)	[1]
Financing activities		(2,547)	(2,405)	[1]
Net cash provided by discontinued operations		94,484	138,133	[1]
Cash transferred from discontinued operations to continuing operations		46,080	371,656	[1]
Effect of exchange rate changes on cash and cash equivalents		2,405	21,051	[1]
Net increase (decrease) in cash and cash equivalents		(73,642)	206,900	[1]
Cash and cash equivalents at beginning of period		359,923	630,433	[1]
Cash and cash equivalents at end of period		$ 286,281	$ 837,333	[1]

[1] Reclassified to conform to current presentation (see Note A).