Stock-Based Compensation, Option Plans (Details) - Stock Options - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Stock-Based Compensation
Total intrinsic value of stock options exercised (in dollars)	$ 140.3	$ 215.8
Total fair value of stock options vested (in dollars)	2.3	$ 2.3
Total compensation cost related to non-vested options not yet recognized (in dollars)	$ 270.9
Weighted average expected amortization period	3 years 3 months 14 days