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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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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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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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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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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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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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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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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 of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 10,196	$ 9,261	$ 6,966
Total intrinsic value of options exercised	1,145	14,534	7,656
Income tax benefit from the exercise of stock options	$ 78	4,512	2,224
Range One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Life (Years)	2 years 8 months 12 days
Range Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Life (Years)	2 years 7 months 6 days
Range Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Life (Years)	5 years 8 months 12 days
Range Four [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Life (Years)	7 years 3 months 18 days
Range Five [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Remaining Contractual Life (Years)	8 years 8 months 12 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards, term (in years)	10 years
Unrecognized compensation expense	$ 3,755
Unrecognized compensation expense, weighted-average period of recognition (in years)	1 year 3 months 18 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 119
Unrecognized compensation expense, weighted-average period of recognition (in years)	7 months 22 days
Total fair value of shares of restricted stock that vested	$ 8,363	8,831	12,480
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 14,925
Unrecognized compensation expense, weighted-average period of recognition (in years)	2 years 6 months
Total fair value of shares of restricted stock that vested	$ 725	$ 371	$ 14
Ratably On Annual Basis [Member] \| Stock Options [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	1 year
Ratably On Annual Basis [Member] \| Stock Options [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	4 years
Ratably On Annual Basis [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	3 years
Cliff Vest [Member] \| Restricted Stock Units (RSUs) [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	1 year
Cliff Vest [Member] \| Restricted Stock Units (RSUs) [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	6 years
First One Half Increment On Anniversary Of Award Date [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	5 years
Second One Half Increment On Anniversary Of Award Date [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	9 years 6 months
Second One Half Increment On Anniversary Of Award Date [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation, vesting period	9 years 6 months