Stock-Based Compensation Options outstanding and exercisable, by exercise price and weighted average life (Details) (USD $)	9 Months Ended
	Sep. 30, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Option Shares Outstanding	2,394,655
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	5 years 0 months 4 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.02
Options Exercisable, Option Shares Outstanding	1,798,407
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	3 years 8 months 27 days
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.95
$3.03
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 3.03
Options Outstanding, Option Shares Outstanding	787,500
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	2 years 1 month 17 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.03
Options Exercisable, Option Shares Outstanding	787,500
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	2 years 1 month 17 days
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.03
$3.25
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 3.25
Options Outstanding, Option Shares Outstanding	757,963
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	4 years 0 months 26 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 3.25
Options Exercisable, Option Shares Outstanding	757,963
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	4 years 0 months 26 days
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 3.25
$7.62
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 7.62
Options Outstanding, Option Shares Outstanding	60,000
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 11 months 1 day
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.62
Options Exercisable, Option Shares Outstanding	0
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.00
$7.84
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 7.84
Options Outstanding, Option Shares Outstanding	232,500
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 9 months
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.84
Options Exercisable, Option Shares Outstanding	131,676
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	7 years 9 months
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 7.84
$7.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 7.93
Options Outstanding, Option Shares Outstanding	5,000
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.93
Options Exercisable, Option Shares Outstanding	0
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.00
$7.97
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 7.97
Options Outstanding, Option Shares Outstanding	110,000
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	8 years 11 months 1 day
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.97
Options Exercisable, Option Shares Outstanding	36,676
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	8 years 11 months 1 day
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 7.97
$8.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 8.00
Options Outstanding, Option Shares Outstanding	170,000
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	8 years 9 months
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.00
Options Exercisable, Option Shares Outstanding	0
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.00
$8.89
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 8.89
Options Outstanding, Option Shares Outstanding	183,424
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	9 years 3 months
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.89
Options Exercisable, Option Shares Outstanding	0
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 0.00
$11.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price (in dollars per share)	$ 11.00
Options Outstanding, Option Shares Outstanding	88,268
Options Outstanding, Weighted Average Remaining Contractual Life (in years)	7 years 2 months 16 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11.00
Options Exercisable, Option Shares Outstanding	84,592
Options Exercisable, Weighted Average Remaining Contractual Life (in years)	7 years 2 months 16 days
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 11.00