Stockholders' Equity (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Total cost including broker’s commissions	$ 18.1	$ 0.0
Common Class A \| Common Stock
Class of Stock [Line Items]
Shares repurchased	0.8
Average price per share	$ 23.36
Total cost including broker’s commissions	$ 18.1

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The cash outflow to reacquire common stock during the period.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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Number of shares that have been repurchased during the period and are being held in treasury.

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