Defined Contribution Plan, Employer Maximum Matching Contribution, value

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- Definition

Minimum percentage of exercise price granted to ten percentage of shareholders.

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No definition available.

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- Definition

Share based compensation arrangement by share based payment award, aggregate option and employee stock purchase plan, grants in period, weighted average grant date fair value.

+ References

No definition available.

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- Definition

Term Of Stock Appreciation Rights From Date Of Grant

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-Subparagraph (SX 210.5-02.29)
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- Definition

Amount of cost for defined contribution plan.

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- Definition

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

+ References

No definition available.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

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- Definition

Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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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 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.

+ References

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-Paragraph 28
-Subparagraph (a)
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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

Discount rate from fair value on purchase date that participants pay for shares.

+ References

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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

Date the equity-based award expires, in CCYY-MM-DD format.

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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.

+ References

No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

+ References

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- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

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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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- 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

Other than shares newly issued, the number of additional shares issued (for example, a stock split) or canceled (for example, to correct a share issuance), during the period under the plan.

+ References

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- Definition

The weighted average of per share prices paid for shares purchased on the open market for issuance to employees under the plan.

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- Definition

Intrinsic value of equity-based compensation awards vested. Excludes stock and unit options.

+ References

No definition available.

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- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

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No definition available.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Employee Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
Employee Benefit Plans (Narrative) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-cash stock-based compensation	$ 22,147,000	$ 18,949,000	$ 16,825,000
Vesting term (in years)	4 years
Allocation of Recognized Period Costs, Capitalized Amount	$ 500,000	500,000	500,000
Maximum Percentage Contribution Of Salary By Employees	100.00%
Employer Matching Contribution, Percent of Employees' Gross Pay	50.00%
Maximum Contribution By Employer Value	$ 6,000
Cost Recognized	$ 1,000,000	$ 1,000,000	900,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Additional Shares Authorized		1,000,000.0
Number of Shares Authorized		2,000,000.0
Shares purchased under ESPP	111,000
Weighted Average Price of Shares Purchased under ESPP	$ 43.00
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, Exercises in Period, Intrinsic Value	$ 7,700,000	$ 14,500,000	11,400,000
Options, Vested in Period, Total Fair Value	$ 3,800,000	$ 4,200,000	$ 6,500,000
Grants In Period, Weighted Average Grant Date Fair Value	$ 12.35	$ 12.28	$ 10.83
Total unrecognized compensation	$ 7,400,000
Weighted-average period of recognition of stock based compensation (in days)	2 years 6 months 20 days
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation	$ 37,200,000
Weighted-average period of recognition of stock based compensation (in days)	2 years 5 months 15 days
Aggregate Intrinsic Value, Vested	$ 19,500,000	$ 15,400,000	$ 8,900,000
Equity Instruments Other than Options, Vested in Period, Fair Value	$ 14,600,000	10,800,000	8,800,000
2006 Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration Date	Apr. 13, 2016
2016 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum Percentage Of Exercise Price Granted To Ten Percentage Of Shareholders	110.00%
Common Stock, Capital Shares Reserved for Future Issuance	2,500,000.0
Other Share Increase (Decrease)	699,827
Number of shares reserved for future grant (in shares)	1,900,000
Vesting term (in years)	4 years
2016 Incentive Plan [Member] \| SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term Of Stock Appreciation Rights From Date Of Grant	10 years
2016 Incentive Plan [Member] \| First Tranche [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)	12 months
2016 Incentive Plan [Member] \| Remaining Tranche [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)	3 years
2016 Incentive Plan [Member] \| Minimum [Member] \| RSAs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term (in years)	3 years
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum Percentage of compensation contributed by employees (in percentage)	10.00%
Purchase percentage of stock at fair market value (in percentage)	85.00%
Discount from Market Price, Purchase Date	15.00%
Non-cash stock-based compensation	$ 1,500,000	$ 1,300,000	$ 500,000
Number of shares reserved for future grant (in shares)	900,000