Acquisition (Preliminary Purchase Price Allocation) (Details) - USD ($) $ in Thousands	1 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Petrobas America Inc
Business Acquisition [Line Items]
Cash consideration paid		$ 775,413
Fair value of net assets contributed		154,469
Contingent consideration		52,540
NCI in acquired assets		245,605
Total purchase consideration		1,228,027
Fair value of Property, plant and equipment		1,610,790
Other assets		5,628
Less: Asset retirement obligations		(388,391)
Total net assets		1,228,027
LLOG Exploration Offshore L.L.C. and LLOG Bluewater Holdings, L.L.C.
Business Acquisition [Line Items]
Cash consideration paid	$ 1,226,300	1,226,261
Fair value of net assets contributed		0
Contingent consideration		89,444
NCI in acquired assets		0
Total purchase consideration		1,315,705
Fair value of Property, plant and equipment		1,340,206
Other assets		12,771
Less: Asset retirement obligations		(37,272)
Total net assets		$ 1,315,705