Major Customers	12 Months Ended
Dec. 31, 2016
Risks and Uncertainties [Abstract]
Major Customers	MAJOR CUSTOMERS In 2016 and 2015, purchases by China Petroleum & Chemical Corporation and its subsidiaries accounted for 21 percent and 12 percent, respectively, of the Company's worldwide oil and gas production revenues. In 2016 and 2015, purchases by Egyptian General Petroleum Company and its subsidiaries accounted for 12 percent and 11 percent, respectively, of the Company's worldwide oil and gas production revenues. In 2015 and 2014, purchases by Royal Dutch Shell plc and its subsidiaries accounted for 11 percent and 19 percent, respectively, of the Company’s worldwide oil and gas production revenues.

MAJOR CUSTOMERS

In 2016 and 2015, purchases by China Petroleum & Chemical Corporation and its subsidiaries accounted for 21 percent and 12 percent, respectively, of the Company's worldwide oil and gas production revenues. In 2016 and 2015, purchases by Egyptian General Petroleum Company and its subsidiaries accounted for 12 percent and 11 percent, respectively, of the Company's worldwide oil and gas production revenues. In 2015 and 2014, purchases by Royal Dutch Shell plc and its subsidiaries accounted for 11 percent and 19 percent, respectively, of the Company’s worldwide oil and gas production revenues.