Subsequent Event	12 Months Ended
Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Event	20. Subsequent Event In January 2020, the operator, Kosmos Energy Ltd, completed drilling of the Oldfield-1 exploration well in the Gulf of Mexico. The well did not encounter commercial quantities of hydrocarbons and 2019 results include $15 million in exploration expense for well costs incurred through December 31, 2019. We estimate approximately $15 million of exploration expense will be recognized in the first quarter of 2020 for well costs incurred after December 31, 2019.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Name:	us-gaap_SubsequentEventsTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration