Income taxes

6 Months Ended

Jun. 30, 2011

INCOME TAXES [Abstract]

Income taxes

Income taxes. Federal income taxes for the interim periods presented have been included in the accompanying financial statements on the basis of an estimated annual effective tax rate.  As of June 30, 2011, the estimated annual effective tax rate for 2011 is about 27 percent, which differs from the 35 percent statutory corporate tax rate primarily due to the effects of non-U.S. tax rates.