Employee Benefit Plan (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Benefit Plan (Textual) [Abstract]
Portion of matching eligible compensation contributed to the plan by employer, First	100.00%
Percentage of eligible compensation contributed to the plan by employees, First	3.00%
Portion of matching eligible compensation contributed to the plan by employer, Second	50.00%
Percentage of eligible compensation contributed to the plan by employees, Second	2.00%
Company's contributions to the plan	$ 0.5	$ 0.5	$ 0.5