Components of Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 30.0	$ 38.3	$ 59.2	$ 79.4
Other comprehensive (loss) income
Derivative contracts (decrease) increase	(0.7)	6.7	1.2	(1.5)
Total comprehensive income	$ 29.3	$ 45.0	$ 60.4	$ 77.9