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The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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Equity and Other Comprehensive Income (Loss) - Additional Information (Details) $ / shares in Units, MMBTU in Millions, $ in Millions	9 Months Ended
	Jun. 30, 2022 USD ($) MMBTU $ / shares shares	Jun. 30, 2021 shares	May 04, 2022 shares	Sep. 30, 2021 $ / shares	Jul. 31, 2015 $ / shares shares
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Stock repurchase program, number of shares authorized to be repurchased			25,000,000.0		40,000,000.0
Common Stock, Par or Stated Value Per Share \| $ / shares	$ 0.01			$ 0.01	$ 0.01
Authorized share repurchase as a percentage of common stock outstanding			10.00%		15.00%
Stock repurchase program, remaining number of shares authorized to be repurchased	29,000,000.0
Treasury stock, shares, acquired	12,600,000	0
Purchases of common stock \| $	$ 597.5
Natural Gas Commodity Hedge [Member] \| Cash Flow Hedge [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Notional amount of natural gas derivatives \| MMBTU	14.4
Derivative liability \| $	$ 31.3
Minimum [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Effective Tax Rate, Net of Tax Components of Other Comprehensive Income	24.00%	23.00%
Maximum [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%