Stock-Based Compensation (Outstanding Stock Options Grants) (Details) (Stock Options, Common Stock, USD $)	12 Months Ended
Dec. 31, 2013
$1.64 - $2.25
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	$ 3.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	1,102,082
Weighted- Average Remaining Contractual Life (Years)	4 years 5 months 4 days
Weighted- Average Exercise Price	$ 2.87
Granted Stock Options Exercisable	1,101,874
Weighted- Average Exercise Price	$ 2.87
$2.26 - $2.62
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 3.68
Exercise Price Range, Upper Range Limit	$ 5.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	1,106,288
Weighted- Average Remaining Contractual Life (Years)	5 years 8 months 1 day
Weighted- Average Exercise Price	$ 4.47
Granted Stock Options Exercisable	558,692
Weighted- Average Exercise Price	$ 4.32
$4.26 - $4.42
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 5.72
Exercise Price Range, Upper Range Limit	$ 7.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	323,597
Weighted- Average Remaining Contractual Life (Years)	5 years 11 months 1 day
Weighted- Average Exercise Price	$ 6.63
Granted Stock Options Exercisable	166,732
Weighted- Average Exercise Price	$ 6.23
$4.50 - $7.09
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 7.76
Exercise Price Range, Upper Range Limit	$ 9.79
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	444,541
Weighted- Average Remaining Contractual Life (Years)	7 years 5 months 4 days
Weighted- Average Exercise Price	$ 8.55
Granted Stock Options Exercisable	258,956
Weighted- Average Exercise Price	$ 8.43
$7.26 - $9.46
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 9.80
Exercise Price Range, Upper Range Limit	$ 11.83
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	248,332
Weighted- Average Remaining Contractual Life (Years)	7 years 9 months 3 days
Weighted- Average Exercise Price	$ 11.02
Granted Stock Options Exercisable	94,614
Weighted- Average Exercise Price	$ 11.18
$10.00 - $13.60
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 11.84
Exercise Price Range, Upper Range Limit	$ 13.87
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	308,689
Weighted- Average Remaining Contractual Life (Years)	8 years 9 months 7 days
Weighted- Average Exercise Price	$ 13.19
Granted Stock Options Exercisable	56,212
Weighted- Average Exercise Price	$ 13.11
$13.68 - $14.95
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 13.88
Exercise Price Range, Upper Range Limit	$ 15.91
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	708,954
Weighted- Average Remaining Contractual Life (Years)	8 years 10 months 9 days
Weighted- Average Exercise Price	$ 14.45
Granted Stock Options Exercisable	92,809
Weighted- Average Exercise Price	$ 14.53
$14.98 - $17.86
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 15.92
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	128,343
Weighted- Average Remaining Contractual Life (Years)	9 years 6 months 10 days
Weighted- Average Exercise Price	$ 16.42
Granted Stock Options Exercisable	0
Weighted- Average Exercise Price	$ 0.00
$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	4,370,826
Weighted- Average Remaining Contractual Life (Years)	6 years 6 months 7 days
Weighted- Average Exercise Price	$ 7.60
Granted Stock Options Exercisable	2,329,889
Weighted- Average Exercise Price	$ 5.13

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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

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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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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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- 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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(iii)

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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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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a, b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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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

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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

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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

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