Consolidated Statement Of Stockholders' Equity (USD $) In Thousands | Common Stock [Member] | Additional Paid In Capital [Member] | Retained Earnings [Member] | Accumulated Other Comprehensive Income, Net Of Taxes [Member] | Treasury Stock, At Cost [Member] | Total |
|---|---|---|---|---|---|---|
| Beginning Balance at Dec. 31, 2010 | $ 23,121 | $ 41,085 | $ 767,126 | $ 7,807 | $ (159,667) | $ 679,472 |
| Excess of proceeds over cost of treasury stock sold | 12 | |||||
| Net income | 20,430 | 20,430 | ||||
| Stockholder dividends of $0.81 per share | (9,287) | |||||
| Other comprehensive income | 37,207 | 37,207 | ||||
| Cost of 122,301 shares acquired | (3,741) | |||||
| Cost of 723 shares sold | 10 | |||||
| Ending Balance at Sep. 30, 2011 | $ 23,121 | $ 41,097 | $ 778,269 | $ 45,014 | $ (163,398) | $ 724,103 |