Fair Value Measurement (Details) (USD $)	1 Months Ended			1 Months Ended															3 Months Ended
	Jan. 31, 2011 HCL-EMS Minimum	Jan. 31, 2011 HCL-EMS Maximum	Jan. 25, 2011 Level 3 HCL-EMS Income approach	Jan. 31, 2011 Level 3 Contingent consideration HCL-EMS Income approach	Jan. 31, 2011 Level 3 Contingent consideration HCL-EMS Income approach Minimum	Jan. 31, 2011 Level 3 Contingent consideration HCL-EMS Income approach Maximum	Mar. 31, 2013 Recurring basis Total	Dec. 31, 2012 Recurring basis Total	Mar. 31, 2013 Recurring basis Total Contingent consideration HCL-EMS	Dec. 31, 2012 Recurring basis Total Contingent consideration HCL-EMS	Mar. 31, 2013 Recurring basis Total Money market institutional funds	Dec. 31, 2012 Recurring basis Total Money market institutional funds	Mar. 31, 2013 Recurring basis Level 1	Dec. 31, 2012 Recurring basis Level 1	Mar. 31, 2013 Recurring basis Level 1 Money market institutional funds	Dec. 31, 2012 Recurring basis Level 1 Money market institutional funds	Mar. 31, 2013 Recurring basis Level 3	Dec. 31, 2012 Recurring basis Level 3	Mar. 31, 2013 Recurring basis Level 3 Contingent consideration HCL-EMS	Dec. 31, 2012 Recurring basis Level 3 Contingent consideration HCL-EMS
Fair value measurement
Cash and cash equivalents											$ 23,315,000	$ 28,094,000			$ 23,315,000	$ 28,094,000
Recognized amount									1,891,000	2,046,000									1,891,000	2,046,000
Total							25,206,000	30,140,000					23,315,000	28,094,000			1,891,000	2,046,000
Percentage of specified revenues from specified customers acquired, used in determining contingent consideration	7.50%	15.00%
Contingent consideration recognized			3,400,000
Discount rate assumption, used in determining contingent consideration (as a percent)				10.50%
Probability adjusted levels of revenue assumption, used in determining contingent consideration					12,600,000	13,900,000
Changes in the fair value of the Level 3 liability
Balance, Beginning of Period																			2,046,000
Imputed interest																			12,000
Second year earn-out adjustment																			(167,000)
Balance, End of Period																			$ 1,891,000