Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Oct. 31, 2016	Apr. 30, 2016	Oct. 31, 2015
Statement of Financial Position [Abstract]
Treasury Stock, Shares	39,085,220	39,701,409	40,138,877
Allowance for doubtful accounts	$ 56,062	$ 57,011	$ 53,340
Allowance for loan losses	5,484	5,518	7,412
Accumulated depreciation and amortization	$ 647,689	$ 601,120	$ 563,158
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	250,578,382	260,218,666	276,087,566