Segment Information (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Segment Reporting Information [Line Items]
Total revenues	$ 2,562,990	$ 199,770	$ 134,340	$ 127,195	$ 2,200,212	$ 471,979	$ 137,263	$ 96,489	$ 3,024,295	$ 2,905,943	$ 2,893,771
Assets	4,693,529				4,537,779				4,693,529	4,537,779	4,649,567
Foreign
Segment Reporting Information [Line Items]
Total revenues									232,200	249,000	232,800
Assets	$ 303,900				$ 472,600				$ 303,900	$ 472,600	$ 201,800