v3.6.0.2

Stock-based Compensation - Additional Information (Detail) - USD ($) | 12 Months Ended
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Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Stock Based Compensation [Line Items] |  |  |
Compensation expense related to incentive plans | $ (100,000) | $ 5,800,000 | $ 4,800,000
Non-Voting Time-Vested Restricted Stock Units [Member] |  |  |
Stock Based Compensation [Line Items] |  |  |
Weighted average grant date fair value | $ 20.07 | $ 30.17 |
Aggregate value of vested shares | $ 200,000 | $ 900,000 |
Recognized / Unrecognized compensation cost | $ 1,500,000 |  |
Weighted average period | 1 year 3 months |  |
Aggregate value of forfeited shares |  | $ 200,000 |
Non-Voting Time-Vested Restricted Stock Units [Member] | Maximum [Member] |  |  |
Stock Based Compensation [Line Items] |  |  |
Aggregate value of forfeited shares | $ 100,000 |  |
Non-Voting Performance Based Restricted Stock Units [Member] |  |  |
Stock Based Compensation [Line Items] |  |  |
Weighted average grant date fair value | $ 15.71 |  |
Aggregate value of vested shares | $ 3,200,000 |  |
Recognized / Unrecognized compensation cost | 14,700,000 |  |
Aggregate value of forfeited shares | 400,000 |  |
Reduction in compensation expense | $ (2,800,000) |  |
2012 Long - Term Incentive Plan [Member] | Amended and Restated 2015 Long Term Incentive Plan [Member] |  |  |
Stock Based Compensation [Line Items] |  |  |
Shares available for issuance | 499,460 |  |
Forfeiture restrictions percentage | 100.00% |  |
Vesting period of employees | 3 years |  |
2012 Long - Term Incentive Plan [Member] | Amended and Restated 2015 Long Term Incentive Plan [Member] | Non-Voting Common Stock [Member] |  |  |
Stock Based Compensation [Line Items] |  |  |
Common stock authorized to issue | 1,500,000 |  |

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- Definition Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period Fair Value + References No definition available. + Details
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- Definition Stock Based Compensation [Line Items] + References No definition available. + Details
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- Definition Time vested restricted stock units forfeiture restrictions lapsation percentage. + References No definition available. + Details
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- Definition Time vested restricted stock units forfeiture restrictions lapsation period. + References No definition available. + Details
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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. + References 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) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation. + References No definition available. + Details
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- Definition The increase (decrease) during the reporting period in the obligation created by employee agreements whereby earned compensation will be paid in the future. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
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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). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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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). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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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 + Details
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