Share-Based Payments (Tables)

12 Months Ended

Apr. 30, 2014

Share-Based Payments [Abstract]

Summary of restricted shares, deferred shares, deferred stock units, and performance units

	Restricted Shares and Deferred Stock Units		Weighted-Average Grant Date Fair Value		Performance Units		Weighted-Average Conversion Date Fair Value
Outstanding at May 1, 2013		985,214	$	59.64		106,666	$	100.54
Granted		167,134		101.08		101,020		104.91
Converted		106,666		100.54		(106,666)		100.54
Vested		(402,081)		51.77		—		—
Forfeited		(17,745)		74.86		—		—
Outstanding at April 30, 2014		839,188	$	76.54		101,020	$	104.91

Weighted-average grant date fair values of the equity awards

Year Ended April 30,	Restricted Shares and Deferred Stock Units		Weighted-Average Grant Date Fair Value		Performance Units		Weighted-Average Conversion Date Fair Value
2014		167,134	$	101.08		101,020	$	104.91
2013		109,770		76.37		106,666		100.54
2012		152,180		78.32		99,455		76.37