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Stock-based Compensation Plans (Narrative) (Details) $ / shares in Units, $ in Millions |  | 3 Months Ended
--- | --- | ---
Dec. 02, 2020 | Dec. 31, 2020 USD ($) $ / shares shares | Dec. 31, 2019 USD ($) shares
Share-based Payment Arrangement, Expense | $ |  | $ 2.5 | $ 1.9
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | $ |  | $ 14.1 |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount |  | 258,522 | 108,976
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares |  | 63,433 |
Phantom Share Units (PSUs) [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instrument Other than Option, Nonvested, Intrinsic Value | $ / shares |  | $ 12.38 |
Share-based compensation liability | $ |  | $ 1.3 |
Granted, shares |  | 180,987 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 11.86 |
Granted, shares |  | 180,987 |
Performance Shares [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period |  | 103,058 |
Share-based compensation, units awarded but not yet granted |  | 204,520 |
Restricted Stock Units (RSUs) [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period |  | 125,576 |
Granted, shares |  | 129,081 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 11.86 |
Granted, shares |  | 129,081 |
Market Based Performance Shares |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate | 1.77% |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate | 0.21% |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term | 2 years 9 months 29 days |  |
Granted, shares |  | 234,199 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate | 1.77% |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 15.39 |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate | 0.21% |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term | 2 years 9 months 29 days |  |
Granted, shares |  | 234,199 |
Equity Option |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate |  | 2.01% |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate |  | 0.66% |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term |  | 6 years |
Granted, shares |  | 423,405 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate |  | 2.01% |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 3.05 |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate |  | 0.66% |
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term |  | 6 years |
Granted, shares |  | 423,405 |
Minimum [Member] | Performance Shares [Member] |  |  |
Performance Factors |  | 0 |
Minimum [Member] | Market Based Performance Shares |  |  |
Performance Factors |  | 0 |
Maximum [Member] | Performance Shares [Member] |  |  |
Performance Factors |  | 2 |
Maximum [Member] | Market Based Performance Shares |  |  |
Performance Factors |  | 2 |
Share-based Payment Arrangement, Tranche Two [Member] | Performance Shares [Member] |  |  |
Granted, shares |  | 60,019 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 11.86 |
Granted, shares |  | 60,019 |
Share-based Payment Arrangement, Tranche Three [Member] | Performance Shares [Member] |  |  |
Granted, shares |  | 84,483 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares |  | $ 11.86 |
Granted, shares |  | 84,483 |

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