Condensed Consolidated Statements of Shareholder’s Equity (Deficit) and Noncontrolling Interests - USD ($) $ in Millions	Total	Madison Industries IAQ Solutions Corporation	Madison Industries IAQ Solutions Corporation Total Shareholder's Equity (Deficit)	Madison Industries IAQ Solutions Corporation Common Stock	Madison Industries IAQ Solutions Corporation Additional Paid-In Capital	Madison Industries IAQ Solutions Corporation Retained Earnings (Accumulated Deficit)	Madison Industries IAQ Solutions Corporation Accumulated Other Comprehensive Income (Loss)	Madison Industries IAQ Solutions Corporation Noncontrolling Interest
Beginning balance (in shares) at Dec. 31, 2024				1,000
Beginning balance at Dec. 31, 2024		$ (92.5)	$ (58.1)	$ 0.0	$ 0.0	$ (17.4)	$ (40.7)	$ (34.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions		9.8	9.8		9.8
Net income (loss)		43.2	37.7			37.7		5.5
Other comprehensive income (loss)		(3.7)					(3.1)
Other comprehensive income (loss)		(3.5)	(3.2)				(3.2)	(0.3)
Ending balance (in shares) at Mar. 31, 2025				1,000
Ending balance at Mar. 31, 2025		(43.0)	(13.8)	$ 0.0	9.8	20.3	(43.9)	(29.2)
Beginning balance at Dec. 31, 2024		437.2
Redeemable Noncontrolling Interest
Contributions from noncontrolling interests		0.2
Redemptions of noncontrolling interests		(0.2)
Net income (loss)		3.0
Other comprehensive income (loss)		(0.2)
Ending balance at Mar. 31, 2025		$ 440.0
Beginning balance (in shares) at Dec. 31, 2025	1,000	1,000		1,000
Beginning balance at Dec. 31, 2025		$ 82.1	(37.0)	$ 0.0	0.0	(6.3)	(30.7)	119.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Distributions		14.3	14.3		14.3
Increased value of redeemable noncontrolling interests		(1.5)	(1.5)		(1.5)
Equity appreciation rights		8.1	0.0		0.0			8.1
Net income (loss)		38.7	33.6			33.6		5.1
Other comprehensive income (loss)		$ 1.6	1.7				1.7	(0.1)
Ending balance (in shares) at Mar. 31, 2026	1,000	1,000		1,000
Ending balance at Mar. 31, 2026		$ 143.3	$ 11.1	$ 0.0	$ 12.8	$ 27.3	$ (29.0)	$ 132.2
Beginning balance at Dec. 31, 2025		882.9
Redeemable Noncontrolling Interest
Increased value of redeemable noncontrolling interests		1.5
Net income (loss)		4.3
Ending balance at Mar. 31, 2026		$ 888.7