Property, Plant and Equipment Narrative - (Details) $ in Thousands		3 Months Ended	12 Months Ended
	Jul. 31, 2019 USD ($) entity	Mar. 31, 2020 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Well Costs		$ 178,433		$ 217,326	$ 227,126	$ 207,855
Exploratory well costs capitalized more than one year		153,800
Impairment of oil and gas Properties		967,530
Athabasca Oil Corporation | Canadian Subsidiary
Property, Plant and Equipment [Line Items]
Cost of acquired assets, carried interest			$ 168,000
Malaysia Subsidiaries
Property, Plant and Equipment [Line Items]
Number of businesses divested | entity	2
Cash received from divestiture	$ 2,000,000
Gain (loss) on disposition of business	960,000
Contingent bonus payment	$ 100,000
Brunei
Property, Plant and Equipment [Line Items]
Exploratory well costs capitalized more than one year		24,200
Vietnam
Property, Plant and Equipment [Line Items]
Exploratory well costs capitalized more than one year		86,000
Gulf of Mexico
Property, Plant and Equipment [Line Items]
Exploratory well costs capitalized more than one year		16,400
United States
Property, Plant and Equipment [Line Items]
Exploratory well costs capitalized more than one year		27,300
Impairment of oil and gas Properties		$ 927,821
Kaybob Duvernay Lands, Alberta | Canadian Subsidiary
Property, Plant and Equipment [Line Items]
Interest in assets acquired			70.00%
Placid Montney Lands, Alberta | Canadian Subsidiary
Property, Plant and Equipment [Line Items]
Interest in assets acquired			30.00%