Common Stock Incentive Plan (Details) - $ / shares	3 Months Ended	6 Months Ended
Mar. 31, 2020	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested Restricted Shares, Beginning Balance	139,546	80,937
Unvested Restricted Shares, Granted	15,918	1,139
Unvested Restricted Shares, Vested	(45,975)	(4,675)
Unvested Restricted Shares, Forfeited	(28,552)
Unvested Restricted Shares, Ending Balance	80,937	77,401
Weighted-Average Grant Date Fair Value, Beginning Balance	$ 37.03	$ 50.64
Weighted-Average Grant Date Fair Value, Granted	75.11	87.82
Weighted-Average Grant Date Fair Value, Vested	37.01	62.08
Weighted-Average Grant Date Fair Value, Forfeited	19.72
Weighted-Average Grant Date Fair Value, Ending Balance	$ 50.64	$ 50.49
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested Restricted Shares, Beginning Balance	0	33,954
Unvested Restricted Shares, Granted	33,954	2,733
Unvested Restricted Shares, Ending Balance	33,954	36,687
Weighted-Average Grant Date Fair Value, Beginning Balance	$ 0	$ 75.11
Weighted-Average Grant Date Fair Value, Granted	75.11	87.82
Weighted-Average Grant Date Fair Value, Ending Balance	$ 75.11	$ 76.06

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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)(1)(iv)(3)
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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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-Publisher FASB
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-Topic 718
-SubTopic 10
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-Paragraph 2
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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

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-Publisher FASB
-Name Accounting Standards Codification
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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

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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-Name Accounting Standards Codification
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-Paragraph 2
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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

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-Publisher FASB
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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-Publisher FASB
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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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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.

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No definition available.

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