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Number of Shares Granted for Each Year Served

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The total fair value of shares issued during the period under a deferred compensation arrangement.

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The number of shares issued pursuant to the terms of the deferred compensation plan as of the balance sheet date.

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As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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-Glossary Financing Activities

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The noncash expense that represents the cost of restricted stock or unit distributed to employees as compensation.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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The maximum number of shares (or other type of equity) that have been approved for issuance in the equity-based payment transaction.

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Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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Number of share options (or share units) exercised during the current period.

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The noncash expense that accounts for the value of stock or unit options distributed to employees as compensation.

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Stock Compensation (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
Stock Compensation (Narrative) (Details) (USD $)	Jan. 31, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of stock granted				$ 51.63
Options and restricted stock units authorized to grant		863,000		863,000
Exercise of stock options, shares				24,600
Proceeds from the exercise of stock options				$ 1,050,000	$ 6,382,000
Number of units, vested				29,890
1997 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares covered under stock option and incentive plan		1,500,000		1,500,000
2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares covered under stock option and incentive plan		1,500,000		1,500,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of options granted				$ 5.38	$ 6.08
Dividend yield				2.90%	3.30%
Expected volatility				13.90%	17.50%
Expected life (in years)				5	5
Risk-free interest rate				1.70%	2.40%
Stock options expense		113,000	135,000	375,000	376,000
Exercise of stock options, shares				24,600	192,936
Aggregate intrinsic value of the stock options exercised				457,000	4,000,000
Unamortized compensation expense		1,300,000		1,300,000
Weighted average recognized period of unamortized compensation expenses (in years)				3.4
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value of stock granted				$ 51.63	$ 54.44
Restricted stock units expense		241,000	347,000	729,000	1,200,000
Number of units, vested				29,890	43,757
Aggregate fair value of the shares vested				1,700,000	2,400,000
Unamortized compensation expense		2,300,000		2,300,000
Weighted average recognized period of unamortized compensation expenses (in years)				3.5
Stock compensation, net, shares				18,907	27,037
Retirement Plan for Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved for issuance				70,000
Number of shares granted for each year served				1,000
Maximum number of shares issued upon retirement				5,000
Compensation expense under retirement plan		26,000	36,000	97,000	117,000
Unamortized compensation expense		242,000	375,000	242,000	375,000
Shares issued to a director upon retirement					0
Aggregate fair value of shares issued	$ 290,000
Stock compensation, net, shares	5,000