Summary of Significant Accounting Policies Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Accounting Policies [Abstract]
Treasury money market funds, at fair value	$ 131.2		$ 131.2		$ 153.2
Deferred Costs	15.1		15.1		$ 15.1
Amortization of Deferred Charges	$ 1.1	$ 1.4	$ 3.6	$ 4.4