XML 27 R16.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Income taxes
6 Months Ended
Jun. 30, 2011
Income taxes [Abstract]  
Income taxes
8.  Income Taxes

The Company files U.S. federal income tax returns and various state and local income tax returns.  With few exceptions, years prior to 2007 are no longer subject to examination. The Company is under audit in the state of Maryland for the 2007, 2008 and 2009 tax years.   No other state or federal income tax audits were in process as of June 30, 2011.