Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 470.6	$ 502.5	$ 556.8
Marketable securities:
Unrealized gain (loss)	0.0	0.0	0.1
Reclassifications:
Amortization of unrealized (gain) loss to interest expense	0.0	0.0	0.6
Total	0.0	0.0	0.7
Deferred income tax expense (benefit)	0.0	0.0	0.2
Other comprehensive income (loss)	0.0	0.0	0.5
Comprehensive income	$ 470.6	$ 502.5	$ 557.3