Parent Company Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities
Net income (loss) attributable to the Parent Company	$ 131.3	$ (35.4)	$ 196.4
Reconciliation of Net income (loss) attributable to the Parent Company to net cash provided by (used in) operating activities:
Net cash provided by operating activities	208.0	152.2	49.1
Cash flows from investing activities:
Net cash provided by (used in) investing activities	81.2	48.9	(120.7)
Cash flows from financing activities:
Other financing activities, net	3.7	1.1	2.9
Net cash used in financing activities	(253.4)	(120.8)	(79.3)
Change in cash and cash equivalents	35.8	80.3	(150.9)
Cash, cash equivalents and restricted cash, beginning of the year	801.2	719.0	890.3
Cash, cash equivalents and restricted cash, end of the year	814.6	801.2	719.0
Supplemental disclosure of non-cash activities:
Stock-based compensation	35.6	54.1	40.3
Parent Company
Cash flows from operating activities
Net income (loss) attributable to the Parent Company	131.3	(35.4)	196.4
Reconciliation of Net income (loss) attributable to the Parent Company to net cash provided by (used in) operating activities:
(Income) loss in earnings of subsidiaries	(131.2)	35.3	(196.1)
Net cash provided by operating activities	0.1	(0.1)	0.3
Cash flows from investing activities:
Net cash provided by (used in) investing activities	0.0	0.0	0.0
Cash flows from financing activities:
Other financing activities, net	4.2	0.7	2.6
Net cash used in financing activities	4.2	0.7	2.6
Change in cash and cash equivalents	4.3	0.6	2.9
Cash, cash equivalents and restricted cash, beginning of the year	22.3	21.7	18.8
Cash, cash equivalents and restricted cash, end of the year	26.6	22.3	21.7
Supplemental disclosure of non-cash activities:
Stock-based compensation	$ 35.6	$ 54.1	$ 40.3