Excess tax benefit if there was no net operating loss carry forwards.

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Excess tax expense benefit due to carryforward loss.

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Period option is available to be exercised.

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Share based compensation arrangement by share based payment award options and restricted stock vested in period fair value.

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Share based compensation arrangement by share based payment award percentage of target number of shares to be issued.

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Share based compensation arrangement by share based payment award target number of shares to be issued.

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Share-based Compensation Arrangement by Share-based Payment Award, Performance Calculation Period

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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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Unrecognized cost of unvested share-based compensation awards.

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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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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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

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Percentage of vesting of share-based compensation awards.

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Number of share options (or share units) exercised during the current period.

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Incentive Plan - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
Incentive Plan - Narrative (Details) - USD ($)	Mar. 24, 2016	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation expenses			$ 2,200,000	$ 3,300,000	$ 7,400,000	$ 10,500,000
Tax benefit			1,200,000			3,800,000
Unrecognized compensation related to non-vested share-based compensation arrangements			$ 10,300,000		$ 10,300,000
Weighted-average period over which unrecognized compensation cost related to non-vested share-based compensation arrangements is expected to be recognized					1 year 8 months 12 days
Total fair value of share-based awards vested					$ 2,500,000	5,200,000
Vesting periods		3 years
Total intrinsic value of options exercised						37,000
Stock options exercised					0
Cash received from option exercises					$ 0	727,000
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit if there was no net operating loss carryforwards						11,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax benefit due to carryforward loss					0	0
Excess tax benefit if there was no net operating loss carryforwards					$ 0	0
Options expiration period					10 years
Cash received from option exercises						$ 724,000
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting periods					3 years
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting periods					5 years
Performance-based Phantom Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance calculation period	2 years
Target number of shares to be issued	705,263
Performance-based Phantom Stock Awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target number of shares to be issued	0.00%
Performance-based Phantom Stock Awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target number of shares to be issued	150.00%
Phantom Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting periods					3 years
Shares issued					552,100
Year One \| Performance-based Phantom Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation vesting percentage					50.00%
Year One \| Phantom Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation vesting percentage					33.33%
Year Two \| Performance-based Phantom Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation vesting percentage					50.00%
Year Two \| Phantom Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation vesting percentage					33.33%
Year Three \| Phantom Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation vesting percentage					33.33%