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Stock Compensation Plans - Schedule of Restricted Stock Units ("RSUs"), Performance Stock Units ("PSUs"), and Restricted Stock Awards ("RSAs") Granted (Detail) - shares shares in Thousands | 12 Months Ended
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Mar. 31, 2023 | Mar. 31, 2022 | Mar. 31, 2021
Performance Vested Restricted Stock [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Total Shares Awarded |  |  | 88 | 54
Performance Vested Restricted Stock [Member] | Director [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] |  | 0 | 0
Performance Vested Restricted Stock [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] |  | 88 | 54
Time Vested Restricted Stock [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Total Shares Awarded |  |  | 76 | 59
Time Vested Restricted Stock [Member] | Director [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] |  | 22 | 21
Time Vested Restricted Stock [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] |  | 0 | 0
Time Vested Restricted Stock Units (RSUs) [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Total Shares Awarded |  | 126 |  |
Time Vested Restricted Stock Units (RSUs) [Member] | Director [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 37 |  |
Time Vested Restricted Stock Units (RSUs) [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 33 |  |
Performance Vested Performance Stock Units (PSU) [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Total Shares Awarded |  | 112 |  |
Performance Vested Performance Stock Units (PSU) [Member] | Director [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 0 |  |
Performance Vested Performance Stock Units (PSU) [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 112 |  |
Time Vest One-Third Per Year [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 56 | 54 | 38
Performance Vest One-Third Per Year [Member] | Officers and Key Employees [Member] |  |  |  |
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] |  |  |  |
Restricted stock awarded | [1] | 0 | 0 | 0
[1] | Subject to the terms of the applicable award.

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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://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(01) -URI https://asc.fasb.org/extlink&oid=128089324&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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- Definition Gross number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(01) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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