Common Stock, Capital Shares Reserved For Future Issuance, Annual Increase Percent

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Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Award Types

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Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Participants

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Share-Based Compensation Arrangement By Share-based Payment Award, Number Of Shares Exchanged

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Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Weighted Average Participation Threshold

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Aggregate number of common shares reserved for future issuance.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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).

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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Net number of non-option equity instruments granted to participants.

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Number of shares authorized for issuance under share-based payment arrangement.

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Percentage of vesting of award under share-based payment arrangement.

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Value of stock issued during the period upon the conversion of units. An example of a convertible unit is an umbrella partnership real estate investment trust unit (UPREIT unit).

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Share-based Compensation - Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 30, 2019 shares	Jan. 01, 2018 $ / shares shares	Sep. 30, 2019 USD ($) $ / shares	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) award_type participant performance_target $ / shares shares	Sep. 30, 2018 USD ($)	Mar. 31, 2019 USD ($) award_type performance_target $ / shares shares	Mar. 31, 2018 USD ($) $ / shares	Mar. 31, 2017 USD ($) $ / shares	Jul. 31, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of award types \| award_type							2
Number of shares exchanged (in shares)		356,792
Weighted average grant date fair value of units granted (in dollars per share) \| $ / shares							$ 3.62	$ 0.82	$ 0.01
Total unrecognized compensation cost \| $							$ 18,500
Total fair value of units vested \| $							92,000	$ 22,600	$ 300
Share-based compensation expense \| $			$ 154,746	$ 23,030	$ 196,171	$ 36,228	71,151	22,294	349
Effect of reorganization \| $			278,248		$ 278,248
Management Incentive Units and Appreciation Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of award types \| award_type					2
Share-based compensation expense \| $			145,300				$ 71,200	$ 22,300	$ 300
Number of participants impacted by the modification \| participant					306
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognition					3 years 10 months 24 days
Share-based compensation expense \| $			1,800
Share based compensation cost not yet recognized \| $			$ 43,400		$ 43,400
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares			$ 16.00		$ 16.00		$ 0
Total unrecognized compensation cost \| $			$ 35,100		$ 35,100
Weighted average period of recognition						2 years
Number of awards granted (in shares)					2,855,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares			$ 16.06		$ 16.06		$ 0
Total unrecognized compensation cost \| $			$ 51,400		$ 51,400
Weighted average period of recognition						3 years 2 months 12 days
Number of awards granted (in shares)					3,595,000
Management Incentive Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units authorized for issuance (in units)							24,100,000
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares							$ 0.36	$ 0.10
Number of awards granted (in shares)							1,780,900
Appreciation Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units authorized for issuance (in units)							800,000
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares							$ 1.18	$ 0.17
Number of awards granted (in shares)							349,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance targets \| performance_target							4
Vesting percentage							25.00%
Time-Vested Units \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage							25.00%
Award vesting period							1 year
Requisite service period							48 months
Time-Vested Units \| Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage							75.00%
Award vesting period					36 months
Requisite service period							3 years
Unvested restricted stock and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense \| $			$ 7,700
Number of awards granted (in shares)					6,449,483
Restricted Stock And Restricted Stock Units, Performance-Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of performance targets \| performance_target					4
Vesting percentage					25.00%
Number of awards granted (in shares)					696,873
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares		$ 0.00
Weighted average period of recognition							1 year
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average participation threshold, units outstanding (dollars per share) \| $ / shares		$ 0.55
Weighted average period of recognition							1 year 6 months
Equity Incentive Plan 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	52,000,000
Annual increase in shares reserved for future issuance based off of shares outstanding	4.00%
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance (in shares)	6,250,000									6,250,000
Award Period One \| Restricted Stock And Restricted Stock Units, Time-Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted (in shares)					3,379,170
Award Period One \| Restricted Stock And Restricted Stock Units, Time-Based \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Award vesting period					1 year
Award Period One \| Restricted Stock And Restricted Stock Units, Time-Based \| Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					75.00%
Award vesting period					36 months
Award Period Two \| Restricted Stock And Restricted Stock Units, Time-Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted (in shares)					2,323,440
Award Period Two \| Restricted Stock And Restricted Stock Units, Time-Based \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Award vesting period					1 year
Award Period Two \| Restricted Stock And Restricted Stock Units, Time-Based \| Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					75.00%
Award vesting period					3 years
Award Period Three \| Restricted Stock And Restricted Stock Units, Time-Based
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of awards granted (in shares)					50,000