Noncash Share-based Compensation (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Noncash Share-based Compensation (Narrative) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized		900,000
Shares available for future grants	1,043,938	1,043,938
Unrecognized compensation cost related to share-based compensation	$ 43,718,000	$ 43,718,000
Weighted average period to recognize cost, in years		2 years 6 months 10 days
Share-based compensation arrangement by share-based payment, Minimum Employee Subscription rate		1.00%
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate	10.00%	10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date		15.00%	5.00%
Maximum Amount Contributable by employees under ESPP- Half yearly		$ 5,000
Maximum Amount Contributable By Employees Under ESPP- Annually		$ 10,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans		23,848
ESPP contributions by Employees		$ 621,000
RSUs
Noncash Share-based Compensation (Narrative) [Line Items]
Awards, other than options, granted in period	765,260	1,317,642
Weighted average grant date fair value, per share, of awards granted in period	$ 11.19	$ 11.41
MSUs
Noncash Share-based Compensation (Narrative) [Line Items]
Awards, other than options, granted in period		152,500
Weighted average grant date fair value, per share, of awards granted in period		$ 14.29
Employee Stock [Member]
Noncash Share-based Compensation (Narrative) [Line Items]
Shares reserved for issuance under Plan	425,155	425,155
2007 Equity Incentive Plan [Member]
Noncash Share-based Compensation (Narrative) [Line Items]
Shares reserved for issuance under Plan	9,968,000	9,968,000

ESPP contributions by Employees

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Maximum Amount Contributable By Employees Under ESPP- Annually

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Maximum Amount Contributable by employees under ESPP- Half yearly

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- Definition

Share-based compensation arrangement by share-based payment, Minimum Employee Subscription rate

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No definition available.

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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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No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ 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)
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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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Discount rate from fair value on offering date that participants pay for shares.

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The number of grants made 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).

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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).

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- Definition

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

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- Definition

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

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No definition available.

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

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