Stock-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares of common stock authorized for share based payment awards under 2011 Plan	2,600,000
Shares available for grant under the 2011 plan	1,217,210
Compensation expenses (income) charged against income	$ 12,618	$ 4,374	$ (69)
Common stock market value, per share	$ 81.48	$ 49.69
Income tax benefit (expense) recognized in the income statement for share-based compensation arrangements	$ 4,761	$ 1,654	(26)
Proceeds from stock option exercises	$ 4,017	777	1,754
Actual tax benefit recognized for the tax deductions from stock based compensation		$ 442	$ 640
Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	2 years
Weighted-average grant-date fair values of options awarded	$ 14.70	$ 15.59	$ 23.77
Intrinsic values of options exercised	$ 6,620	$ 1,426	$ 2,071
Unrecognized compensation cost	$ 895
Weighted average period for amortization of unrecognized compensation cost	1 year 1 month 6 days
Actual tax benefit recognized for the tax deductions from stock based compensation	$ 1,899	$ 351	$ 568
Stock Option [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of expiration	10 years
Stock Option [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of expiration	8 years
Performance Stock Award [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance stock awards vested	0
Stock Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost	$ 5,514
Weighted average period for amortization of unrecognized compensation cost	1 year 8 months 12 days
Performance stock awards vested	32,319
Weighted-average grant-date fair values of awards granted	$ 41.81	$ 39.11	$ 59.52
Stock Appreciation Rights (SARs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of expiration	10 years
Vesting period	2 years
Unrecognized compensation cost	$ 1,859
Weighted average period for amortization of unrecognized compensation cost	1 year 1 month 6 days
Weighted-average grant-date fair values of awards granted	$ 14.69	$ 15.60	$ 23.74
SARs liability cash-settled	$ 5,832	$ 2,593

Allocated share based compensation expense (income).

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- Definition

Employee service share based compensation tax benefit (expense) from compensation expense.

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- Definition

Stock appreciation rights liabilities noncurrent.

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- Definition

Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 740
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65880886&loc=d3e23524-113945

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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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

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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- 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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- Definition

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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