Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Apr. 30, 2014	Apr. 30, 2013
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 52,578	$ 50,399
Allowance for loan losses	11,272	14,314
Accumulated depreciation and amortization	$ 446,049	$ 420,318
Common stock, no par value	$ 0	$ 0
Common stock, stated value per share	$ 0.01	$ 0.01
Common stock, shares authorized	800,000,000	800,000,000
Common stock, shares issued	316,628,110	316,628,110
Convertible preferred stock, stated value per share	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized	500,000	500,000