CONSOLIDATED STATEMENTS OF ASSETS AND LIABILITIES (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Investments at market or fair value
Companies more than 25% owned, Cost	$ 12,814	$ 14,870
Companies 5% to 25% owned, Cost	15,594	14,003
Companies less than 5% owned, Cost	59,220	60,120
Total investments, Cost	$ 87,628	$ 88,993
Net Assets
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	5,000,000	5,000,000
Common stock, issued (in shares)	4,383,271	4,339,416
Treasury stock (in shares)	584,878	584,878
Shares outstanding (in shares)	3,798,393	3,754,538