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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the par value method.

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Authorized share repurchase as a percentage of common stock outstanding.

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Equity and Other Comprehensive Income (Loss) - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	May 04, 2022	Sep. 30, 2021	Jul. 31, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Stock repurchase program, number of shares authorized to be repurchased					40,000,000.0
Common Stock, Par or Stated Value Per Share	$ 0.01			$ 0.01	$ 0.01
Authorized share repurchase as a percentage of common stock outstanding					15.00%
Stock repurchase program, remaining number of shares authorized to be repurchased	9,400,000
Treasury stock, shares, acquired	7,200,000	0
Purchases of common stock	$ 332.1
Subsequent Event [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Stock repurchase program, number of shares authorized to be repurchased			25,000,000.0
Authorized share repurchase as a percentage of common stock outstanding			10.00%
Minimum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	25.00%	24.00%
Maximum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	26.00%	25.00%