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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
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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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- Definition

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

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-Publisher FASB
-Name Accounting Standards Codification
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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).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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- Definition

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

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-Name Accounting Standards Codification
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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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- Definition

Number of share instruments newly issued under a share-based compensation plan.

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Equity-Based Compensation - Restricted Stock Awards with Service Conditions Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended						3 Months Ended			12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015	Jan. 31, 2015	Feb. 28, 2014	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Executive Officer \| Common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in period (in shares)				20,000
Share-based compensation expense									$ 0.3
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted (in shares)										340,566	555,680	581,672
Number of shares, vested (in shares)										2,816,884	766,159	785,820
Number of shares forfeited in period (in shares)										167,712	626,319	70,299
Weighted Average Grant Date Fair Value, Granted (in dollars per share)										$ 13.87	$ 8.37	$ 15.48
Restricted stock \| Employees And Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted (in shares)						1,377,500
Vesting period						4 years
Number of shares, vested (in shares)							339,375	344,375
Number of shares forfeited in period (in shares)											10,000
Restricted stock \| Non-Management Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted (in shares)					18,200
Second Amended And Restated Non Management Director Compensation Plan [Member] \| Restricted stock \| Non-Management Board of Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, granted (in shares)	54,310	72,397	140,416
Vesting period		1 year
Number of shares forfeited in period (in shares)										514
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	$ 13.95	$ 9.02