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Equity (Details Textual) - USD ($) $ / shares in Units, $ in Thousands |  |  | 6 Months Ended
--- | --- | --- | ---
Mar. 05, 2018 | Dec. 14, 2017 | Jan. 31, 2018 | Jan. 31, 2017 | Oct. 31, 2016
Equity (Textual) |  |  |  |  |
Dividends paid per share in cash |  |  | $ 0.38 |  |
Proceeds from exercise of stock options |  |  |  | $ 835 |
Common Stock [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Aggregate dividends paid on common stock including Class A and Class B. |  |  | $ 9,400 |  | $ 8,800
Common Class A [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Dividends paid per share in cash |  |  | $ 0.38 |  | $ 0.38
Common Class A [Member] | Subsequent Event [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Dividends paid per share in cash | $ 0.09 |  |  |  |
Paid date of declared dividend | Mar. 23, 2018 |  |  |  |
Record date of declared dividend | Mar. 19, 2018 |  |  |  |
Common Class B [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Dividends paid per share in cash |  |  | $ 0.38 | $ 0.38 |
Class B common stock shares purchased options |  |  | 8,000,000 |  |
Stock repurchase program, remaining number of shares authorized to be repurchased |  |  | 8,000,000 |  |
Common Class B [Member] | Subsequent Event [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Dividends paid per share in cash | $ 0.09 |  |  |  |
Paid date of declared dividend | Mar. 23, 2018 |  |  |  |
Record date of declared dividend | Mar. 19, 2018 |  |  |  |
Common Class B [Member] | Employee [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Aggregate purchase price of shares repurchased |  |  | $ 100 | $ 1,800 |
Class B common stock shares repurchased |  |  | 5,170 | 94,338 |
Common Class B [Member] | 2015 Stock Option and Incentive Plan [Member] |  |  |  |  |
Equity (Textual) |  |  |  |  |
Additional shares available stock option incentive plan for grants |  | 300,000 |  |  |
Proceeds from exercise of stock options |  |  |  | $ 800,000 |
Stock issued for stock option exercises |  |  |  | 73,471 |

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- Definition Aggregate dividends paid during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
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