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Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 19,629	$ 15,755
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Restricted stock granted			1,234,320
Granted, weighted average grant date fair value per unit			$ 13.08
Stock-based compensation expense	$ 5,000	$ 5,200	$ 16,800	13,400
Restricted Stock [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate			0.00%
Restricted Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate			16.90%
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted			425,590
Granted, weighted average grant date fair value per unit			$ 11.20
Stock-based compensation expense	$ 1,000	$ 800	$ 2,900	$ 2,300
Right to received shares of common stock	1		1
Performance share units initial performance period, years			3 years
Grant date fair value amortization term			4 years
Number of trading days			30 days
Performance Share Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate			2.40%
PSU granted percentage of earnings			0.00%
Performance Share Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual forfeiture rate			4.90%
PSU granted percentage of earnings			200.00%
PSU 2015 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value amortization term			4 years
Expected percentage earned	86.00%		86.00%

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- Definition

The rate of forfeitures assumptions that is used in calculating the fair values of a share-based compensation award.

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Number Of Trading Days Consider For Average Closing Price

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Percentage Of Performance Share Awards Based On Shareholder Return

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Rights Received For Each Performance Share Unit1

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- Definition

The initial performance period for the performance share units.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Output, Expected Percentage Earned

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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-Name Accounting Standards Codification



-Topic 230



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- Definition

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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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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- Definition

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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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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Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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