The maximum amount allowed for advance payroll deductions in a calendar year for employee stock purchase plan.

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- Definition

Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Annual Forfeiture Rate

+ References

No definition available.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Grant Date Fair Value Of Awards

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- Definition

Share Based Compensation Arrangement by Share based Payment Award, Vesting Percentage

+ References

No definition available.

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- Definition

Share Based Compensation Arrangements By Share Based Payment Award Percentage Of Market Price At Eligible Employees Granted Options To Purchase Shares

+ References

No definition available.

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- Definition

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

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- Definition

Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to excess tax benefit for share-based compensation cost.

+ References

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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

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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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

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.

+ References

No definition available.

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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

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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Share-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of average closing price to be paid by employees		85.00%
Share-based compensation		$ 3,592,000	$ 2,827,000	$ 2,600,000
Estimated pre-vesting forfeiture rate (as a percent)		2.20%
Income tax benefit related to adoption of ASU 2016-09		$ 644,000	935,000
Aggregate intrinsic value of stock options exercised		1,685,000	1,728,000
Stock options exercised		1,598,000	$ 2,398,000	$ 2,602,000
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock purchases through advance payroll deductions in a calendar year		$ 25,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option term		10 years
Stock options vesting percentage		100.00%
Unrecognized compensation expense	$ 0	$ 0
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period		6 months
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period		2 years
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period		3 years
Unrecognized compensation expense	7,031,000	$ 7,031,000
Unrecognized compensation expense expected recognition period		1 year 5 months
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	0	$ 0
Grant date fair value of ESPP options	$ 21,000