Fair Value (Details) - Level 1 [Member] - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Term Loan Facility [Member]
Fair Value [Abstract]
Fair value of debt	$ 1,906	$ 2,074
Standard Bank Term Loan Facility [Member]
Fair Value [Abstract]
Fair value of debt	218	0
Senior Notes Due 2025 [Member]
Fair Value [Abstract]
Fair value of debt	439	368
Senior Notes Due 2026 [Member]
Fair Value [Abstract]
Fair value of debt	610	518
Tikon Loan [Member]
Fair Value [Abstract]
Fair value of debt	$ 20	$ 0

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

No definition available.

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant