Fair Value Measurements (Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation) (Details) (USD $)	3 Months Ended
Jul. 26, 2013	Jul. 27, 2012
Fair Value Measurements [Abstract]
Beginning Balance		$ 5,508,768
Net purchases	0	0
Transfers in/(out) of Level 3	0	0
Other-than-temporary impairment included in net income	0	(4,058,768)
Ending Balance		$ 1,450,000

Amount of debt securities categorized neither as held-to-maturity nor trading.

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+ Details