Employment Benefit Plans Other Details (Details) number in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Contribution Plan Disclosure [Line Items]
401(k) matching expense	$ 41	$ 36	$ 35
Multiemployer Plan, insurance premiums paid	$ 59	$ 64	$ 75
Average number of employees covered under multi-employer benefit plans	37	37	35
Retiree Health and Welfare Benefits
Defined Contribution Plan Disclosure [Line Items]
Projected Benefit Obligation	$ 224
Service cost	$ 1