Stockholders' Equity and Stock-Based Compensation (Summary of Share Activity) (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Preferred stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	0.0	1.7	3.4
Balance, end of period	0.0	0.0	1.7
Preferred stock | Conversion of MCPS to common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of MCPS to common stock (in shares)	0.0	(1.7)	(1.7)
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	880.5	869.3	855.7
Issuance of common stock attributable to stock-based compensation	3.8	2.6	2.6
Balance, end of period	884.3	880.5	869.3
Common stock | Conversion of MCPS to common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of MCPS to common stock (in shares)	0.0	8.6	11.0