v3.23.1
Earnings per share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2023
Dec. 31, 2022
Jun. 30, 2022
Mar. 31, 2022
Dec. 31, 2021
Mar. 31, 2023
Mar. 31, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Net earnings $ 40.0 $ 49.0     $ 60.0    
Mandatory preferred stock dividends 0.0     $ 0.0   $ 0.0 $ (4.0)
Net earnings attributable to common shareholders $ 40.0     $ 19.0   $ 89.0 $ 75.0
Weighted Average Number of Shares Outstanding, Basic 71,500     70,400   71,400 68,600
Basic net (loss)/earnings per common share- continuing operations (in dollars per share) $ 0.56     $ 0.27   $ 1.25 $ 1.09
Weighted Average Number of Shares Outstanding, Diluted 72,400     71,600   72,300 69,000
Diluted net (loss)/earnings per common share- continuing operations (in dollars per share) $ 0.55     $ 0.27   $ 1.23 $ 1.09
Net earnings $ 40.0     $ 19.0   $ 89.0 $ 79.0
Basic net (loss)/earnings per common share (in dollars per share) $ 0.56     $ 0.27   $ 1.25 $ 1.09
Performance Shares              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 1,300     1,600   1,300 1,600
Restricted Stock Equivalents              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 100     400   200 300
Deferred Compensation, Share-based Payments              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Effect of dilutive performance shares (shares) 0     100   100 100
Common Stock              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Stock Issued During Period, Shares, Conversion of Convertible Securities     4,700 4,687      
Retained (Losses)/Earnings              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Net earnings $ 40.0 $ 49.0     60.0    
Mandatory preferred stock dividends         $ (4.0)    
Net earnings $ 40.0     $ 19.0      
Performance Shares              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Effect of dilutive performance shares (shares) 500     100   500 200
Restricted Stock Equivalents              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Effect of dilutive performance shares (shares) 400     100   300 100
MCPS              
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]              
Effect of dilutive performance shares (shares) 0     900   0 0