Debt (Schedule of Revolving Credit Facility) (Details) - Senior Unsecured Revolving Credit Facility [Member] - Revolving Credit Facility [Member] - USD ($) $ in Millions				9 Months Ended
		Sep. 30, 2021	Aug. 05, 2021	Sep. 30, 2021
Line of Credit Facility [Line Items]
Proceeds from Lines of Credit				$ 400
Repayments of Lines of Credit			$ 396	400
Borrowings outstanding	[1]	$ 0		0
Line of Credit Facility, Remaining Borrowing Capacity	[2]	$ 1,250		$ 1,250
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.25%

[1] The Company borrowed $400 million under its senior unsecured revolving credit facility to repay the 5.875% senior unsecured notes due June 15, 2021 and repaid $400 million under its senior unsecured revolving credit facility during the nine months ended September 30, 2021.

[2] The margin for borrowings under the senior unsecured revolving credit facility was 1.25% above LIBOR or EURIBOR at current Company credit ratings.