Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Numerator:
Income from continuing operations	$ 203,057	$ 173,182
Loss from discontinued operations	(15)
NET INCOME	203,042us-gaap_NetIncomeLoss	173,182us-gaap_NetIncomeLoss
Adjustment for basic earnings per share:
Earnings allocated to unvested shareholders	(1,255)	(992)
Numerator for basic earnings per share:
From continuing operations	201,802	172,190
From discontinued operations	(15)
Net income (loss) attributable to parent, basic	201,787	172,190
Adjustment for diluted earnings per share:
Effect of reallocating undistributed earnings of unvested shareholders	6	7
Numerator for diluted earnings per share:
From continuing operations	201,808	172,197
From discontinued operations	(15)
Net income (loss) attributable to parent, diluted	$ 201,793	$ 172,197
Denominator:
Denominator for basic earnings per share - weighted-average shares	107,973	107,149
Effect of dilutive shares from stock options and restricted stock (in shares)	870	1,428
Denominator for diluted earnings per share - adjusted weighted-average shares	108,843	108,577
Basic earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.87	$ 1.61
Net income (in dollars per share)	$ 1.87us-gaap_EarningsPerShareBasic	$ 1.61us-gaap_EarningsPerShareBasic
Diluted earnings per common share:
Income from continuing operations (in dollars per share)	$ 1.85	$ 1.59
Net income (in dollars per share)	$ 1.85us-gaap_EarningsPerShareDiluted	$ 1.59us-gaap_EarningsPerShareDiluted
Outstanding equity awards
Shares excluded from calculation of diluted earnings per share	669	261
Weighted-average price per share (in dollars per share)	$ 72.87	$ 79.67

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This element represents the income or loss from continuing operations adjusted for undistributed earnings allocated to participating securities in the calculation of basic earnings per share.

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This element represents the income or loss from continuing operations adjusted for undistributed earnings allocated to participating securities and the effect of reallocating undistributed earnings of unvested shareholders in the calculation of diluted earnings per share.

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Represents the weighted-average price per share of the shares excluded from the calculation of diluted earnings per share because their inclusion would have been anti-dilutive.

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Amount of increase (decrease) to net income used for calculating diluted earnings per share (EPS), resulting from the assumed exercise of stock options or restrictive stock units (RSUs).

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Net Income or Loss Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.

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Amount of undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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