Organization (Details) - USD ($) $ in Millions			3 Months Ended		9 Months Ended
	Oct. 03, 2019	Jul. 31, 2014	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2015	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Restructuring			$ 1.9	$ 1.6		$ 2.8	$ 1.7
Restructuring and other charges			1.4	2.4
Payments			1.1	0.5
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage	51.00%	49.00%
Pension costs (benefits) other then service			$ (0.8)	$ (0.7)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%	21.00%
Payments to acquire interest in joint venture					$ 1.7
Proceeds from Other Equity, Gross Amount			$ 4.8
Intercompany Loan related to NMTC			12.2
Investment Fund Contribution for NMTC			16.5
Sub-CDE loan from NMTC			16.2
Restricted Cash			2.2			$ 0.0
Mueller Co. [Member]
Segment Reporting Information [Line Items]
Restructuring and other charges			$ 0.1	$ 0.0