Debt and Equity - Purchase of Senior Notes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Aug. 05, 2022
Debt Instrument [Line Items]
Gain/(Loss)	$ 8	$ 0	$ 8	$ 0
Senior Notes
Debt Instrument [Line Items]
Principal Amount	582		582
Discounts/Deferred Issuance Costs	6		6
Book Value	576
Redemption Value	558		558
Gain/(Loss)	18
Senior Notes | Subsequent event
Debt Instrument [Line Items]
Principal Amount					$ 291
Redemption Value					$ 273
5.00% Senior Note due 2027 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	85		85
Discounts/Deferred Issuance Costs	1		1
Book Value	84
Redemption Value	85		85
Gain/(Loss)	(1)
4.125% Senior Note due 2028 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	90		90
Discounts/Deferred Issuance Costs	1		1
Book Value	89
Redemption Value	85		85
Gain/(Loss)	4
4.375% Senior Note due 2028 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	106		106
Discounts/Deferred Issuance Costs	1		1
Book Value	105
Redemption Value	102		102
Gain/(Loss)	3
5.25% Senior Note due 2029 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	85		85
Discounts/Deferred Issuance Costs	1		1
Book Value	84
Redemption Value	82		82
Gain/(Loss)	2
4.25% Senior Note due 2030 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	17		17
Discounts/Deferred Issuance Costs	0		0
Book Value	17
Redemption Value	16		16
Gain/(Loss)	1
4.625% Senior Note due 2030 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	66		66
Discounts/Deferred Issuance Costs	1		1
Book Value	65
Redemption Value	62		62
Gain/(Loss)	3
5.40% Senior Note due 2034 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	15		15
Discounts/Deferred Issuance Costs	0		0
Book Value	15
Redemption Value	15		15
Gain/(Loss)	0
5.450% Senior Note due 2043 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	118		118
Discounts/Deferred Issuance Costs	1		1
Book Value	117
Redemption Value	111		$ 111
Gain/(Loss)	$ 6