Amount of discretionary contributions made by an employer to a defined contribution plan.

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

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- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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Amount of noncash expense for share-based payment arrangement.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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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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No definition available.

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- Definition

Number of additional shares authorized for issuance under share-based payment arrangement.

+ References

No definition available.

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Number of shares authorized for issuance under share-based payment arrangement.

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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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- Definition

Gross number of share options (or share units) granted during the period.

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No definition available.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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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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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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

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Share-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands			12 Months Ended
	May 11, 2017	Apr. 16, 2012	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 08, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			$ 11,115	$ 13,031	$ 12,557
Income tax benefit related to share-based compensation			$ 2,300	$ 2,700	$ 2,600
Number of options vested (in shares)			1,300,000
Options exercised (in shares)			435,000	1,117,000	803,000
Aggregate intrinsic value of options exercised			$ 6,000
Weighted average exercise price for options vested (in dollars per share)			$ 12.39
Weighted average remaining contractual term			4 years 10 months 6 days
Options vested aggregate value			$ 12,900
Unrecognized compensation cost related to non-vested stock options			$ 200
Unrecognized compensation cost, period for recognition			10 months 9 days
Employer matching contribution, percent of match (up to)			100.00%
Employer matching contribution, percent of employees' gross pay (up to)			5.00%
Contribution amount			$ 2,200	$ 2,500	$ 1,600
Options granted (in shares)			0	163,000	383,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			1,062,000	1,202,000	1,753,000	2,065,000
Fair value of shares vested			$ 11,700
Weighted average remaining contractual life of RSUs outstanding			1 year 5 months 8 days	1 year 5 months 26 days
Unrecognized compensation cost related to RSUs			$ 8,800	$ 7,200
Restricted Stock Units (RSUs) \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based awards vesting period (in years)			1 year
Restricted Stock Units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based awards vesting period (in years)			5 years
RSUs Subject to Service Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			1,000,000.0
RSUs Subject to Service and Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units outstanding (in shares)			100,000
2012 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be reserved for issuance (in shares)		5,500,000
2012 Stock Incentive Plan \| Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be reserved for issuance (in shares)		3,850,000
Expiration period (not more than)		10 years	10 years
Award requisite service period		3 years
2012 Stock Incentive Plan \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be reserved for issuance (in shares)		1,650,000
2014 Omnibus Incentive Plan \| Common Class A
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized to be reserved for issuance (in shares)	6,000,000.0						4,000,000.0
Additional shares authorized (in shares)	2,000,000.0