Business and Asset Actions - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Restructuring and Related Activities [Abstract]
Business and asset actions, including equity affiliate income	$ 2,934.7		$ 2,934.7
Business and asset actions, including equity affiliate income, attributable to Air Products after tax	2,290.6		2,290.6
Business and asset actions	$ 2,927.9	$ 57.0	$ 2,927.9	$ 57.0
Business and asset actions attributable to Air Products after tax		$ 43.8		$ 43.8