State research and development credit exchange receivable	12 Months Ended
Dec. 31, 2012
State research and development credit exchange receivable	3. State research and development credit exchange receivable The State of Connecticut provides certain companies with the opportunity to exchange certain research and development income tax credit carryforwards for cash in exchange for forgoing the carryforward of the research and development income tax credits. The program provides for an exchange of research and development income tax credits for cash equal to 65% of the value of corporation tax credit available for exchange. Estimated amounts receivable under the program are recorded as a reduction of research and development expenses. During the years ended December 31, 2010, 2011 and 2012, research and development expenses were offset by $385,000, $609,000 and $289,000, respectively, in connection with the program.

3. State research and development credit exchange receivable

The State of Connecticut provides certain companies with the opportunity to exchange certain research and development income tax credit carryforwards for cash in exchange for forgoing the carryforward of the research and development income tax credits. The program provides for an exchange of research and development income tax credits for cash equal to 65% of the value of corporation tax credit available for exchange. Estimated amounts receivable under the program are recorded as a reduction of research and development expenses. During the years ended December 31, 2010, 2011 and 2012, research and development expenses were offset by $385,000, $609,000 and $289,000, respectively, in connection with the program.