Stock-Based Compensation (Outstanding Stock Options Grants) (Details) (Employee Stock Option, Common Stock, USD $)	12 Months Ended
Dec. 31, 2014
$1.64 - $2.94
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 1.64
Exercise Price Range, Upper Range Limit	$ 2.94
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	724,715
Weighted- Average Remaining Contractual Life (Years)	3 years 3 months 18 days
Weighted- Average Exercise Price	$ 2.58
Granted Stock Options Exercisable	724,715
Weighted- Average Exercise Price	$ 2.58
$2.95 - $4.41
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 2.95
Exercise Price Range, Upper Range Limit	$ 4.41
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	837,352
Weighted- Average Remaining Contractual Life (Years)	4 years 0 months 0 days
Weighted- Average Exercise Price	$ 3.94
Granted Stock Options Exercisable	837,352
Weighted- Average Exercise Price	$ 3.94
$4.42 - $7.25
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 4.42
Exercise Price Range, Upper Range Limit	$ 7.25
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	657,217
Weighted- Average Remaining Contractual Life (Years)	5 years 1 month 6 days
Weighted- Average Exercise Price	$ 5.34
Granted Stock Options Exercisable	573,634
Weighted- Average Exercise Price	$ 5.10
$7.26 - $11.62
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 7.26
Exercise Price Range, Upper Range Limit	$ 11.62
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	670,785
Weighted- Average Remaining Contractual Life (Years)	6 years 8 months 12 days
Weighted- Average Exercise Price	$ 9.41
Granted Stock Options Exercisable	424,706
Weighted- Average Exercise Price	$ 9.14
$11.63 - $13.16
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 11.63
Exercise Price Range, Upper Range Limit	$ 13.16
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	171,048
Weighted- Average Remaining Contractual Life (Years)	8 years 1 month 6 days
Weighted- Average Exercise Price	$ 12.23
Granted Stock Options Exercisable	43,674
Weighted- Average Exercise Price	$ 12.37
$13.17 - $13.24
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 13.17
Exercise Price Range, Upper Range Limit	$ 13.24
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	879,833
Weighted- Average Remaining Contractual Life (Years)	9 years 3 months 18 days
Weighted- Average Exercise Price	$ 13.17
Granted Stock Options Exercisable	108,918
Weighted- Average Exercise Price	$ 13.18
$13.25 - $14.15
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 13.25
Exercise Price Range, Upper Range Limit	$ 14.15
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	654,188
Weighted- Average Remaining Contractual Life (Years)	8 years 3 months 18 days
Weighted- Average Exercise Price	$ 13.81
Granted Stock Options Exercisable	202,493
Weighted- Average Exercise Price	$ 13.84
$14.16 - $17.86
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 14.16
Exercise Price Range, Upper Range Limit	$ 17.86
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	651,174
Weighted- Average Remaining Contractual Life (Years)	8 years 3 months 18 days
Weighted- Average Exercise Price	$ 15.18
Granted Stock Options Exercisable	154,622
Weighted- Average Exercise Price	$ 15.09
$1.64 - $17.86
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 1.64
Exercise Price Range, Upper Range Limit	$ 17.86
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	5,246,312
Weighted- Average Remaining Contractual Life (Years)	6 years 4 months 24 days
Weighted- Average Exercise Price	$ 9.07
Granted Stock Options Exercisable	3,070,114
Weighted- Average Exercise Price	$ 6.22

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ 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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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ 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)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ 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)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ 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)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

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.

+ 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 (e)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ 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 (g)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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