Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity - Narrative (Details)

v3.19.1
Shareholders' Equity - Narrative (Details) - USD ($)
shares in Millions, $ in Millions
3 Months Ended 6 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2019
Mar. 31, 2018
Class of Stock [Line Items]        
Cash dividends paid on common stock     $ 26.2 $ 26.2
Treasury Stock, Value, Acquired, Cost Method   $ 23.7   38.9
Amount of shares repurchased     $ 0.0 $ 38.9
Treasury Stock        
Class of Stock [Line Items]        
Treasury Stock, Shares, Acquired   0.5   0.9
Treasury Stock, Value, Acquired, Cost Method   $ 23.7   $ 38.9
Common stock, shares issued 0.1 0.1 0.3 0.4