Consolidated Statement Of Stockholders' Equity (Parenthetical) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011
Consolidated Statement Of Stockholders' Equity
Issuance of shares of common stock pursuant to the exercise of employee stock options	36
Issuance of shares of common stock pursuant to the employee stock purchase plan	8
Purchase of treasury shares	44
Reclassification adjustment related to marketable securities sold in net unrealized gain position, tax provision	$ 3
Change in fair value on available-for-sale securities, net of deferred income tax	$ 133