Stockholders' Equity (Details)	Jun. 30, 2013	Dec. 31, 2012
Common Stock Reserved for Future Issuance
Common stock awards outstanding (in shares)	2,308,000	1,956,000
Common stock awards available for grant (in shares)	524,000	438,000
Total common shares reserved for future issuance	2,832,000	2,394,000