Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023
Preferred shares, shares authorized (in shares)	10,000,000	10,000,000
Preferred shares, shares issued (in shares)	3,677	3,677
Preferred shares, shares outstanding (in shares)	3,677	3,677
Preferred shares, liquidation preference	$ 3,677	$ 3,677
Common shares, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, shares authorized (in shares)	75,000,000	75,000,000
Common shares, shares issued (in shares)	52,965,797	52,965,797
Common shares, shares outstanding (in shares)	21,042,652	21,042,652
Treasury shares (in shares)	31,923,145	31,923,145