Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Oct. 31, 2013	Apr. 30, 2013	Oct. 31, 2012
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 52,969	$ 50,399	$ 42,761
Allowance for loan losses	12,704	14,314	18,125
Accumulated depreciation and amortization	$ 449,738	$ 420,318	$ 562,178
Common stock, no par value	$ 0	$ 0	$ 0
Common stock, stated value per share	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000	800,000,000
Common stock, shares issued	316,628,110	316,628,110	316,628,110
Convertible preferred stock, stated value per share	$ 0.01	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized	500,000	500,000	500,000