Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Stock-based Compensation (Additional Textual) [Abstract]
Number of options for every share issued	1.75		1.75
Discount from fair market value on purchase date			85.00%
Maximum number of shares per employee			2,000
Maximum value of shares per employee			$ 25,000
Common stock reserved for issuance	1,000,000		1,000,000
Shares purchased by employee since inception of ESPP	482,519		482,519
Shares purchased under ESPP			25,628	28,702
Unrecognized compensation cost	4,900,000		4,900,000
Stock repurchase program, authorized amount			50,000,000
Repurchased shares	581,200	31,214	968,488	31,214
Repurchased shares, value	$ 3,200,000	$ 188,000	$ 5,200,000	$ 188,000
Stock repurchase program, average cost	$ 5.51	$ 6.02	$ 5.42	$ 6.02
Stock Options [Member]
Stock-based Compensation (Textual) [Abstract]
Stock-based payment award vesting period (years)			4 years
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)			2 years 5 months 27 days
Stock Options [Member] | Maximum [Member]
Stock-based Compensation (Textual) [Abstract]
Stock-based payment award expiration period (years)			10 years
Stock Options [Member] | Minimum [Member]
Stock-based Compensation (Textual) [Abstract]
Stock-based payment award expiration period (years)			5 years
Restricted Stock Awards [Member]
Stock-based Compensation (Textual) [Abstract]
Stock-based payment award vesting period (years)			1 year
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)			8 months 1 day
Restricted Stock Units [Member]
Stock-based Compensation (Textual) [Abstract]
Stock-based payment award vesting period (years)			3 years
Unrecognized compensation cost, recognized over an estimated weighted-average period (years)			2 years 4 days