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Income Taxes Income Tax Rate Reconciliation (Details)	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%	21.00%
Adjustments to reconcile to the effective tax rate:
State income taxes, net of federal benefit	4.20%	4.50%	4.20%	4.50%
Valuation allowance adjustment related to stock compensation	0.00%	(0.30%)	0.70%	(0.50%)
Tax benefits from stock compensation	0.00%	0.00%	(0.30%)	(0.60%)
Tax credits	(1.70%)	(1.70%)	(1.70%)	(2.60%)
Effective Income Tax Rate Reconciliation, GILTI, percent	0.50%	(0.20%)	0.50%	(0.10%)
Other	2.60%	1.30%	0.50%	1.50%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(0.40%)	(0.50%)	(0.40%)	(0.60%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Percent	0.60%	1.00%	0.60%	0.60%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Percent	0.60%	1.00%	0.60%	0.60%
Effective Income Tax Rate Reconciliation, Basis Difference in Foreign Investments	1.20%	0.30%	1.20%	0.00%
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Percent	(0.40%)	(0.50%)	(0.40%)	(0.60%)
Effective Income Tax Rate Reconciliation, Fin 48 Statute Release	0.00%	(2.10%)	0.00%	(0.50%)

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Effective Income Tax Rate Reconciliation, Basis Difference in Foreign Investments

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Effective Income Tax Rate Reconciliation, GILTI, percent

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations attributable to deduction. Includes, but is not limited to, dividend deduction, deduction for dividend paid to employee stock ownership plan (ESOP), Medicare prescription drug benefit subsidy deduction, and other deductions.

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Percentage of the difference, between reported income tax expense (benefit) and the expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, that is attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority interest income (expense), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, change in enacted tax rate, prior year income taxes, change in deferred tax asset valuation allowance, and other adjustments.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other tax credits.

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