Stock-Based Compensation (Summary of Option Activity) (Details)	6 Months Ended
Jun. 30, 2016 $ / shares shares
2005 Plan [Member]
Stock Options
Outstanding at January 1, 2016	15,450,542
Granted	0
Exercised	(620,100)
Canceled	(196,000)
Outstanding at June 30, 2016	14,634,442
Shares exercisable at June 30, 2016	10,469,067
Weighted-Average Exercise Price
Outstanding at January 1, 2016 \| $ / shares	$ 3.31
Granted \| $ / shares	0
Exercised \| $ / shares	2.01
Canceled \| $ / shares	4.69
Outstanding at June 30, 2016 \| $ / shares	3.34
Shares exercisable at June 30, 2016 \| $ / shares	$ 2.81
2015 Plan [Member]
Stock Options
Outstanding at January 1, 2016	8,357,003
Granted	10,104,437
Exercised	0
Canceled	(321,052)
Outstanding at June 30, 2016	18,140,388
Shares exercisable at June 30, 2016	1,991,605
Shares available for grant at June 30, 2016	12,814,612
Weighted-Average Exercise Price
Outstanding at January 1, 2016 \| $ / shares	$ 8.97
Granted \| $ / shares	5.04
Exercised \| $ / shares	0
Canceled \| $ / shares	7.29
Outstanding at June 30, 2016 \| $ / shares	6.81
Shares exercisable at June 30, 2016 \| $ / shares	$ 8.97

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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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ 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 (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ 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 (c)(1)(iv)(3)
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Gross number of share options (or share units) granted during the period.

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No definition available.

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Number of options outstanding, including both vested and non-vested options.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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

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