Retirement and Employee Benefit Plans Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 9	$ 9	$ 18
Projected benefit obligation	205	245
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent	22
Accumulated benefit obligation for defined benefit pension plans	3	38
Employer contributions	6	6
Estimated future employer contributions in next fiscal year, cash	3
Estimated future employer contributions in next fiscal year, shares	22
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	40
Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets	118	121
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution expenses related to the defined contribution plans which cover certain employees	$ 30	$ 66	$ 79