Stock Plans (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			6 Months Ended		12 Months Ended	6 Months Ended
	Dec. 31, 2008	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 Equity Incentive Plan [Member] Y D	Jun. 30, 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2011 Employee Stock Purchase Plan [Member]	Jun. 30, 2012 2005 Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unexercised stock options, expiration date (in days)				90
Options to purchase shares of common stock		2,721,191	2,865,390	2,721,191
Restricted stock outstanding				273,080
Common stock authorized to issue under the plan				4,789,841	351,311
Stock option granted vesting period				Stock options granted under the plan expire between the fifth and tenth anniversary of the date of grant and may vest on the third anniversary from the date of grant or may vest twenty-five percent per year over four years.
Service completion period				4
Common stock available for future grants				1,795,570
Total grant date fair value of the options granted	$ 1,026
Unrecognized compensation cost related to unvested share-based compensation arrangements granted, total							$ 13,649
Cost expected to be recognized, years							1 year 5 months 27 days
Common stock discounted percentage					5.00%
Rights to purchase common shares to employees under the ESPP granted					500,000
Common stock purchased under the ESPP					12,504	23,417