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401(k) and Employee Stock Ownership Plan (Details) - USD ($)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]
Employee contribution, percentage of annual salary	100.00%
Employee contribution, maximum allowable contribution	$ 53,000
Term for employees to become fully vested	6 years
Employer matching contribution percent	100.00%
Percent of employees' gross pay	4.00%
Profit sharing contribution, percent	7.00%
Company contributions to plan	$ 8,700,000	$ 7,314,000	$ 5,870,000

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The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 715



-SubTopic 70



-Section 50



-Paragraph 1



-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

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Percentage employer matches of the employee's percentage contribution matched.

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Maximum amount the employee may contribute to a defined contribution plan.

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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

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Term for Employees to Become Fully Vested

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