Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jan. 31, 2014	Apr. 30, 2013	Jan. 31, 2013
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 42,716	$ 50,399	$ 44,829
Allowance for loan losses	11,563	14,314	17,256
Accumulated depreciation and amortization	$ 469,733	$ 420,318	$ 510,052
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