Significant Accounting Policies (Details) - USD ($) shares in Thousands, $ in Millions		3 Months Ended
	Dec. 04, 2017	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Significant Accounting Policies [Line Items]
Operating Lease, Right-of-Use Asset		$ 101		$ 107
Return assets		$ 7		7
Separation Date	Dec. 04, 2017
Weighted Average Number of Shares Outstanding, Basic		86,170	88,450
Intangible assets, net (Excluding Goodwill)		$ 48		53
Goodwill		6		7
Components of net periodic benefit cost other than service cost		(2)	$ 14
Amortization of Intangible Assets		3	$ 6
Operating Lease, Liability, Noncurrent		$ 86		$ 93
Document Period End Date		Mar. 31, 2020