Note K - Accounting for Stock-based Compensation (Details) - Cash-settled Restricted Stock Unit Activity (Cash Settled RSUs [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Cash Settled RSUs [Member]
Note K - Accounting for Stock-based Compensation (Details) - Cash-settled Restricted Stock Unit Activity [Line Items]
Non-vested CSRSUs at December 31, Shares	537,119	200,299
Non-vested CSRSUs at December 31, Weighted-Average Grant Date Fair Value	$ 36.36	$ 28.23
Non-vested CSRSUs at December 31, Aggregate Intrinsic Value	$ 22,011
Granted, Shares	416,432	203,115
Granted, Weighted-Average Grant Date Fair Value	$ 39.12	$ 27.84
Vested	(47,742)
Vested	$ 27.55
Cancelled, Shares	(31,870)	(2,816)
Cancelled, Weighted-Average Grant Date Fair Value	$ 32.12	$ 27.03
CSRSUs expected to vest in the future	497,997
CSRSUs expected to vest in the future	$ 36.32
CSRSUs expected to vest in the future	$ 20,408

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Share based compensation arrangement by share based payment award equity instruments other than options non vested aggregate intrinsic value.

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No definition available.

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

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made 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 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 non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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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 weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan 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.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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