Marketable Securities (Details 1) (USD $)	Apr. 30, 2013	Jul. 31, 2012
Held-to-maturity - Fair Value	$ 76,419	$ 178,176
Available-for-sale - Fair Value	2,420,010	2,215,209
Current [Member]
Held-to-maturity - Cost	125,512	226,397
Held-to-maturity - Gross Unrealized Gains	1,214	2,025
Held-to-maturity - Gross Unrealized Losses	0	0
Held-to-maturity - Fair Value	126,726	228,422
Noncurrent [Member]
Available-for-sale - Cost	2,066,092	1,971,732
Available-for-sale - Gross Unrealized Gains	356,473	259,016
Available-for-sale - Gross Unrealized Losses	2,555	15,539
Available-for-sale - Fair Value	2,420,010	2,215,209
Mutual Funds [Member] \| Noncurrent [Member]
Available-for-sale - Cost	1,554,354	1,255,982
Available-for-sale - Gross Unrealized Gains	227,765	123,203
Available-for-sale - Gross Unrealized Losses	113	0
Available-for-sale - Fair Value	1,782,006	1,379,185
Equity Securities [Member] \| Noncurrent [Member]
Available-for-sale - Cost	511,738	715,750
Available-for-sale - Gross Unrealized Gains	128,708	135,813
Available-for-sale - Gross Unrealized Losses	2,442	15,539
Available-for-sale - Fair Value	638,004	836,024
Certificates Of Deposit [Member] \| Current [Member]
Held-to-maturity - Cost	50,307	50,246
Held-to-maturity - Gross Unrealized Gains	0	0
Held-to-maturity - Gross Unrealized Losses	0	0
Held-to-maturity - Fair Value	50,307	50,246
Corporate Debt Securities [Member] \| Current [Member]
Held-to-maturity - Cost	75,205	176,151
Held-to-maturity - Gross Unrealized Gains	1,214	2,025
Held-to-maturity - Gross Unrealized Losses	0	0
Held-to-maturity - Fair Value	$ 76,419	$ 178,176

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

This item represents the aggregate fair value of investments in debt securities as of the balance sheet date and which are categorized as held-to-maturity.

+ References+ Details

- Definition

As of the balance sheet date, the excess of fair value over carrying value (amortized cost) of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding gain.

+ References+ Details

- Definition

As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. Such item represents the gross unrecognized holding loss.

+ References+ Details