Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Narrative (Details)

v3.20.1
Shareholders' Equity - Narrative (Details) - USD ($)
shares in Millions, $ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Mar. 31, 2020
Mar. 31, 2019
Class of Stock [Line Items]        
Cash dividends paid on common stock     $ 31.7 $ 26.2
Treasury Stock, Value, Acquired, Cost Method     $ (371.3)  
Treasury Stock        
Class of Stock [Line Items]        
Treasury Stock, Shares, Acquired     0.0  
Treasury Stock, Value, Acquired, Cost Method     $ 0.0  
Common stock, shares issued 0.0 0.1 0.1 0.3