Debt (Schedule of Revolving Credit Facility) (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions			6 Months Ended
		Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Borrowings outstanding	[1]	$ 400	$ 400	$ 0
Senior Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Proceeds from Lines of Credit			400
Borrowings outstanding	[2]	400	400
Line of Credit Facility, Remaining Borrowing Capacity	[3]	$ 850	$ 850
London Interbank Offered Rate (LIBOR) [Member] | Senior Unsecured Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.50%

[1] The weighted average interest rate was 1.6% and 0.0% as of June 30, 2021 and December 31, 2020, respectively.

[2] The Company borrowed $400 million under its senior unsecured revolving credit facility to repay the 5.875% senior unsecured notes due June 15, 2021, which matured during the six months ended June 30, 2021.

[3] The margin for borrowings under the senior unsecured revolving credit facility was 1.5% above LIBOR or EURIBOR at current Company credit ratings.