Debt and Equity - Purchase of Senior Notes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Debt Instrument [Line Items]
Gain	$ 5	$ 8	$ 5	$ 8
Senior Notes
Debt Instrument [Line Items]
Principal Amount	131		131
Discounts/Deferred Issuance Costs	1		1
Book Value			130
Redemption Value	125		125
Gain			5
5.00% Senior Notes due March 2027 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	12		12
Discounts/Deferred Issuance Costs	0		0
Book Value			12
Redemption Value	12		12
Gain			0
4.125% Senior Notes Due 2028 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	22		22
Discounts/Deferred Issuance Costs	0		0
Book Value			22
Redemption Value	21		21
Gain			1
4.375% Senior Notes Due 2028 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	6		6
Discounts/Deferred Issuance Costs	0		0
Book Value			6
Redemption Value	5		5
Gain			1
5.25% Senior Notes Due 2029 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	31		31
Discounts/Deferred Issuance Costs	0		0
Book Value			31
Redemption Value	31		31
Gain			0
4.25% Senior Notes Due 2030 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	45		45
Discounts/Deferred Issuance Costs	1		1
Book Value			44
Redemption Value	42		42
Gain			2
4.625% Senior Notes Due 2030 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	15		15
Discounts/Deferred Issuance Costs	0		0
Book Value			15
Redemption Value	$ 14		14
Gain			$ 1