Financial Instruments (Narrative) (Details)			9 Months Ended
	Sep. 30, 2024 USD ($)	Aug. 16, 2023 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Maximum leverage ratio allowed	3.50	3.75	3.50
Maximum leverage ratio allowed, after significant acquisition		4.25
Minimum interest coverage ratio required		3.00
Leverage ratio	0.99		0.99
Interest coverage ratio	15.39		15.39
Line of Credit | Interest rate swaps
Debt Instrument [Line Items]
Derivative, notional amount	$ 350,000,000		$ 350,000,000	$ 350,000,000
All-in interest SOFR rate	2.38%		2.38%
Unsecured Debt | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 800,000,000
Debt instrument, term		5 years
Total spread	1.50%
Borrowings outstanding	$ 360,000,000		$ 360,000,000
Line of credit facility, remaining borrowing capacity	$ 440,000,000		440,000,000
Debt covenant, maximum annual dividend payout amount			$ 40,000,000