Stock-Based Compensation (Outstanding Stock Options Grants) (Details) (Stock Options [Member], Common Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2012
$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	$ 2.25
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	237,196
Weighted- Average Remaining Contractual Life (Years)	5 years 8 months 12 days
Weighted- Average Exercise Price	$ 2.07
Granted Stock Options Exercisable	232,301
Weighted- Average Exercise Price	$ 2.07
$2.26 - $2.62
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 2.26
Exercise Price Range, Upper Range Limit	$ 2.62
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	239,228
Weighted- Average Remaining Contractual Life (Years)	5 years 4 months 24 days
Weighted- Average Exercise Price	$ 2.55
Granted Stock Options Exercisable	238,707
Weighted- Average Exercise Price	$ 2.55
$2.67 - $2.69
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 2.67
Exercise Price Range, Upper Range Limit	$ 2.69
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	442,065
Weighted- Average Remaining Contractual Life (Years)	5 years 4 months 24 days
Weighted- Average Exercise Price	$ 2.67
Granted Stock Options Exercisable	442,065
Weighted- Average Exercise Price	$ 2.67
$2.79 - $3.02
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 2.79
Exercise Price Range, Upper Range Limit	$ 3.02
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	57,658
Weighted- Average Remaining Contractual Life (Years)	4 years 1 month 6 days
Weighted- Average Exercise Price	$ 2.89
Granted Stock Options Exercisable	57,033
Weighted- Average Exercise Price	$ 2.89
$3.35 - $3.45
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 3.35
Exercise Price Range, Upper Range Limit	$ 3.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	154,821
Weighted- Average Remaining Contractual Life (Years)	4 years 4 months 24 days
Weighted- Average Exercise Price	$ 3.42
Granted Stock Options Exercisable	146,281
Weighted- Average Exercise Price	$ 3.42
$3.46 - $3.90
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 3.46
Exercise Price Range, Upper Range Limit	$ 3.90
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	378,248
Weighted- Average Remaining Contractual Life (Years)	4 years 3 months 18 days
Weighted- Average Exercise Price	$ 3.55
Granted Stock Options Exercisable	234,333
Weighted- Average Exercise Price	$ 3.60
$3.92 - $4.31
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 3.92
Exercise Price Range, Upper Range Limit	$ 4.31
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	302,717
Weighted- Average Remaining Contractual Life (Years)	6 years
Weighted- Average Exercise Price	$ 4.14
Granted Stock Options Exercisable	149,193
Weighted- Average Exercise Price	$ 4.10
$4.32 - $4.51
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 4.32
Exercise Price Range, Upper Range Limit	$ 4.51
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	825,479
Weighted- Average Remaining Contractual Life (Years)	7 years
Weighted- Average Exercise Price	$ 4.40
Granted Stock Options Exercisable	391,046
Weighted- Average Exercise Price	$ 4.37
$4.63 - $5.49
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 4.63
Exercise Price Range, Upper Range Limit	$ 5.49
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	284,561
Weighted- Average Remaining Contractual Life (Years)	5 years 8 months 12 days
Weighted- Average Exercise Price	$ 5.26
Granted Stock Options Exercisable	121,597
Weighted- Average Exercise Price	$ 5.03
$5.72 - $7.12
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	$ 7.12
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	403,986
Weighted- Average Remaining Contractual Life (Years)	5 years 9 months 18 days
Weighted- Average Exercise Price	$ 6.31
Granted Stock Options Exercisable	166,458
Weighted- Average Exercise Price	$ 6.23
$7.14 - $8.26
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 7.14
Exercise Price Range, Upper Range Limit	$ 8.26
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	632,754
Weighted- Average Remaining Contractual Life (Years)	8 years 3 months 18 days
Weighted- Average Exercise Price	$ 8.02
Granted Stock Options Exercisable	268,550
Weighted- Average Exercise Price	$ 8.12
$8.57 - $11.68
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 8.57
Exercise Price Range, Upper Range Limit	$ 11.68
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	417,570
Weighted- Average Remaining Contractual Life (Years)	8 years 9 months 18 days
Weighted- Average Exercise Price	$ 10.40
Granted Stock Options Exercisable	78,254
Weighted- Average Exercise Price	$ 10.38
$11.97 - $13.93
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 11.97
Exercise Price Range, Upper Range Limit	$ 13.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	307,693
Weighted- Average Remaining Contractual Life (Years)	9 years 6 months
Weighted- Average Exercise Price	$ 13.32
Granted Stock Options Exercisable	18,150
Weighted- Average Exercise Price	$ 13.53
$14.01 - $15.51
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price Range, Lower Range Limit	$ 14.01
Exercise Price Range, Upper Range Limit	$ 15.51
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	272,754
Weighted- Average Remaining Contractual Life (Years)	9 years 4 months 24 days
Weighted- Average Exercise Price	$ 14.65
Granted Stock Options Exercisable	7,188
Weighted- Average Exercise Price	$ 14.83
$1.64 - $15.51
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	$ 15.51
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Granted Stock Options Outstanding	4,956,730
Weighted- Average Remaining Contractual Life (Years)	6 years 10 months 24 days
Weighted- Average Exercise Price	$ 6.21
Granted Stock Options Exercisable	2,551,156
Weighted- Average Exercise Price	$ 4.35