Percentage Thresholds For Potential Shares To Be Issued

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- Definition

Share Based Compensation Arrangement by Share Based Payment Award, Options, Expiration Term

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- Definition

Share Based Compensation Arrangements By Share Based Payment Award Discount From Market Price

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- Definition

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
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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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- Definition

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

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- Definition

Amount of cash inflow from realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

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- Definition

Amount of cash outflow for realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

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- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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- Definition

Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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- Definition

Amount of cash inflow from exercise of stock options granted under share-based compensation arrangement.

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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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- 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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- 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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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Stock-Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 3,200
Income Tax Expense (benefit)	(150,244)	$ (45,506)	$ 39,757
Payments Related to Tax Withholding for Share-based Compensation	575	450	1,252
Excess Tax Benefit from Share-based Compensation, Operating Activities		1,900
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net			600
Proceeds from Stock Options Exercised	$ 0	0	100
Tax deduction (benefit), excess of compensation		1,900	600
Stock option expiration period from the date of grant				10 years
Vesting Period (in years)				3 years
Stock-based incentive compensation plan, maximum number of shares covered	4,950,000
Number of shares available for grants in future	67,286
Share-based Compensation	$ 6,999	$ 9,983	$ 10,293
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period (in years)	3 years
Performance Shares \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage Thresholds For Potential Shares To Be Issued	0.00%
Vesting Period (in years)	1 year
Performance Shares \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage Thresholds For Potential Shares To Be Issued	150.00%	150.00%	150.00%
Vesting Period (in years)	3 years
Time Based Restricted Stock Units (RSU) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period (in years)	1 year
Time Based Restricted Stock Units (RSU) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period (in years)	3 years
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock based compensation expense	$ 2,500
Unamortized stock based compensation expense, recognition period	1 year 2 months 24 days
Share-based Compensation	$ 5,800	$ 6,800	$ 9,300
Phantom Share Units (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Period (in years)	3 years
Unamortized stock based compensation expense	$ 3,000
Unamortized stock based compensation expense, recognition period	1 year 6 months 27 days
Share-based Compensation	$ 900	2,600	(200)
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based incentive compensation plan, maximum number of shares covered	2,200,000
Share Based Compensation Arrangements By Share Based Payment Award Discount From Market Price	15.00%
Number of shares available for grants in future	902,260
Share-based Compensation	$ 200	$ 600	$ 1,200
Deferred Compensation, Share-based Payments [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income Tax Expense (benefit)	$ 1,900