Stockholders' Equity and Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Stockholder's Equity and Stock-Based Compensation (Textual) [Abstract]
No of shares issued			1,901,334
Estimated weighted average period of recognition of future compensation cost	2 years 8 months 12 days
Restrictions on disposition shares			1,421,418
Stockholder's Equity and Stock-Based Compensation (Additional Textual) [Abstract]
Fair market value of shares issued			$ 5,200,000
Restrictions on disposition lapse over from the date of grant			4 years
Restricted shares granted to employees			412,500
Stock-based compensation expense	1,414,000	1,388,000	2,799,000	2,479,000
Future compensation cost related to non-vested stock options	1,200,000		1,200,000
Restricted stock awards unamortized compensation	$ 9,200,000
Restricted common stock [Member]
Stockholder's Equity and Stock-Based Compensation (Textual) [Abstract]
No of shares issued			1,721,618
Restricted stock units [Member]
Stockholder's Equity and Stock-Based Compensation (Textual) [Abstract]
No of shares issued			179,716
Restrictions on disposition shares			67,416
Restricted Stock Awards [Member]
Stockholder's Equity and Stock-Based Compensation (Textual) [Abstract]
Estimated weighted average period of recognition of future compensation cost			2 years 6 months