Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2011	Mar. 31, 2010
Common Stock [Member]
Common stock, no par value
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	23,240,503	24,325,228
Common stock, shares outstanding	23,240,503	24,325,228
Series A Junior Participating Preferred Stock [Member]
Preferred stock, no par value
Preferred stock, authorized shares	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Series B 6.75% Convertible Perpetual Preferred Stock [Member]
Preferred stock, no par value
Preferred stock, authorized shares	5,000,000	5,000,000
Preferred stock, shares issued	219,999	219,999
Preferred stock, shares outstanding	219,999	219,999