Consolidated Balance Sheets (Parenthetical) (Common Stock [Member], USD $)	Mar. 31, 2012	Mar. 31, 2011
Common Stock [Member]
Consolidated Balance Sheets
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, authorized shares	500,000,000	500,000,000
Common stock, issued shares	139,874,034	150,218,810