Fair Value Measurements - Carrying and Fair Value Amounts (Details) - USD ($)		Jun. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt		$ 30,000,000	$ 155,000,000
Carrying Amount | Significant other observable inputs (Level 2) | 2019 Term Loan Agreement | 2019 Term Loan Agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2019 Term Loan Agreement (Level 2)		800,000,000	800,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2024 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		600,000,000	600,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2027 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		698,000,000	698,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2028 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		795,000,000	795,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2029 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		546,000,000	549,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | 2044 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		531,000,000	550,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Senior Notes | EOIT Senior Notes | EOIT
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		0	251,000,000
Carrying Amount | Significant other observable inputs (Level 2) | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving Credit Facility (Level 2)	[1]	400,000,000	0
Fair Value | Significant other observable inputs (Level 2) | 2019 Term Loan Agreement | 2019 Term Loan Agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
2019 Term Loan Agreement (Level 2)		800,000,000	800,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2024 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		588,000,000	614,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2027 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		648,000,000	698,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2028 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		742,000,000	811,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2029 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		476,000,000	526,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | 2044 Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		424,000,000	506,000,000
Fair Value | Significant other observable inputs (Level 2) | Senior Notes | EOIT Senior Notes | EOIT
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes (Level 2)		0	252,000,000
Fair Value | Significant other observable inputs (Level 2) | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving Credit Facility (Level 2)	[1]	400,000,000	0
Commercial Paper
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term debt	[2]	$ 30,000,000	$ 155,000,000

[1] Borrowing capacity is effectively reduced by our borrowings outstanding under the commercial paper program. $30 million and $155 million of commercial paper was outstanding as of June 30, 2020 and December 31, 2019, respectively.

[2] Short-term debt includes $30 million and $155 million of outstanding commercial paper as of June 30, 2020 and December 31, 2019, respectively.