| **Consolidated Statement Of Equity (USD $)In Thousands** | Common Stock [Member] | Capital Excess Of Par Value [Member] | Retained Earnings [Member] | Treasury Stock [Member] | Accumulated Other Comprehensive Income (Loss) [Member] | Noncontrolling Interest [Member] | Total       |
|----------------------------------------------------------|-----------------------|--------------------------------------|----------------------------|-------------------------|--------------------------------------------------------|----------------------------------|-------------|
| Balance at Dec. 31, 2013                                 | $ 88,964              | $ 743,335                            | $ 729,272                  | $ (27,082)              | $ 346                                                  | $ 208                            | $ 1,535,043 |
| Net income                                               |                  |                                 | 42,859                     |                    |                                                   | 15                               | 42,874      |
| Other comprehensive income, net of income tax of $172    |                  |                                 |                       |                    | 321                                                    |                             | 321         |
| Dividends                                                |                  |                                 | (26,873)                   |                    |                                                   |                             | (26,873)    |
| Repurchase of stock (79,961 shares)                      |                  |                                 |                       | (1,973)                 |                                                   |                             | (1,973)     |
| Equity compensation plan (198,920 shares)                | 100                   | (100)                                |                       |                    |                                                   |                             |        |
| Exercise of stock options (188,736 shares)               | 94                    | 2,663                                |                       |                    |                                                   |                             | 2,757       |
| Stock-based compensation                                 |                  | 1,322                                | (97)                       |                    |                                                   |                             | 1,225       |
| Employee stock plan tax benefits                         |                  | 1,041                                |                       |                    |                                                   |                             | 1,041       |
| Adjustments to Additional Paid in Capital, Other         |                  | (181)                                |                       |                    |                                                   |                             | (181)       |
| Balance at Mar. 31, 2014                                 | $ 89,158              | $ 748,080                            | $ 745,161                  | $ (29,055)              | $ 667                                                  | $ 223                            | $ 1,554,234 |

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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of other increase (decrease) in additional paid in capital (APIC).
+ References
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| - Definition
Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.
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| - Definition
Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after tax and reclassification adjustments of other comprehensive income (loss).
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|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.
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| - Definition
Value, after forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).
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|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Value of stock (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 stock value of such awards forfeited. Stock 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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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Value of stock issued as a result of the exercise of stock options.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.
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