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Stock-based Compensation Plans Grants Table (Details) - USD ($) $ / shares in Units, $ in Millions |  |  |  | 3 Months Ended | 6 Months Ended
--- | --- | --- | --- | --- | ---
Feb. 24, 2020 | Jan. 28, 2020 | Dec. 03, 2019 | Mar. 31, 2020 | Dec. 31, 2019 | Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  |  |  | $ 10.5
Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  | 118,684 | 162,433 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  | $ 12.14 | $ 11.26 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  | $ 1.4 | $ 1.8 |
Employee Stock [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  | 53,876 | 39,492 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  | $ 2.09 | $ 1.97 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  | $ 0.1 | $ 0.1 |
Phantom Share Units (PSUs) [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  |  | 188,973 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  |  | $ 11.26 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  |  | $ 2.1 |
Market Based Performance Shares |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares | 7,498 | 2,763 | 147,213 | 10,261 | 147,213 | 157,474
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | $ 18.17 | $ 16.76 | $ 14.94 | $ 17.79 | $ 14.94 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  | $ 0.2 | $ 2.2 |
Share-based Payment Arrangement, Tranche One [Member] | Performance Shares [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  | 13,682 | 65,428 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  | $ 12.09 | $ 11.26 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  | $ 0.2 | $ 0.7 |
Share-based Payment Arrangement, Tranche Two [Member] | Performance Shares [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  |  | 102,203 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  |  | $ 11.26 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  |  | $ 1.2 |
Share-based Payment Arrangement, Tranche Three [Member] | Performance Shares [Member] |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Granted, shares |  |  |  |  | 44,451 |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  |  |  | $ 11.26 |
Shares Granted, Value, Share-based Payment Arrangement, before Forfeiture |  |  |  |  | $ 0.5 |

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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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