Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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- Definition

Aggregate number of common shares reserved for future issuance.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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- Definition

Gross number of share options (or share units) granted during the period.

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No definition available.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Share-based Compensation - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
	Apr. 21, 2015	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Mar. 01, 2019
Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized		$ 2.7	$ 3.9
Granted (in shares)		423,393	594,536
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation expense		$ 83.5		$ 21.3
Weighted average period for compensation expense expected to be recognized		2 years		1 year 8 months 12 days
RSUs \| Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense recognized		$ 5.0	$ 4.0
2015 Management Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		156,129
2015 Management Incentive Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Expiration period	10 years
Expense recognized		$ 1.4	$ 1.4
Unrecognized share-based compensation expense		$ 0.2		$ 1.6
Weighted average period for compensation expense expected to be recognized		15 days		3 months 19 days
2015 Management Incentive Plan \| RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Assumed Plan \| Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance		1,230,406			2,497,028