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Condensed Financial Information of Registrant (Schedule Of Condensed Financial Information Of Registrant, Statements Of Operations) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended
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Dec. 31, 2012 | Sep. 30, 2012 | Jun. 30, 2012 | Mar. 31, 2012 | Dec. 31, 2011 | Sep. 30, 2011 | Jun. 30, 2011 | Mar. 31, 2011 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010
Revenues: |  |  |  |  |  |  |  |  |  |  |
Net investment income |  |  |  |  |  |  |  |  | $ 131,896 | $ 140,947 | $ 143,814
Net realized investment gains |  |  |  |  |  |  |  |  | 66,380 | 58,397 | 57,089
Total revenues |  |  |  |  |  |  |  |  | 2,783,370 | 2,777,285 | 2,775,885
Expenses: |  |  |  |  |  |  |  |  |  |  |
Other operating expenses |  |  |  |  |  |  |  |  | 207,281 | 215,711 | 255,358
Other operating expenses |  |  |  |  |  |  |  |  | 1,543 | 5,549 | 6,806
Total expenses |  |  |  |  |  |  |  |  | 2,648,060 | 2,532,186 | 2,593,495
Income before income taxes | (39,161) | 91,330 | (18,853) | 101,994 | 110,693 | (18,118) | 75,613 | 76,911 | 135,310 | 245,099 | 182,390
Income tax (benefit) expense |  |  |  |  |  |  |  |  | 18,399 | 53,935 | 30,192
Net income | (17,382) | 66,201 | (5,264) | 73,356 | 79,469 | (3,782) | 57,251 | 58,226 | 116,911 | 191,164 | 152,198
Parent Company [Member] |  |  |  |  |  |  |  |  |  |  |
Revenues: |  |  |  |  |  |  |  |  |  |  |
Net investment income |  |  |  |  |  |  |  |  | 1,114 | 1,411 | 951
Net realized investment gains |  |  |  |  |  |  |  |  | 697 | (1,866) | 1,420
Total revenues |  |  |  |  |  |  |  |  | 1,811 | (455) | 2,371
Expenses: |  |  |  |  |  |  |  |  |  |  |
Other operating expenses |  |  |  |  |  |  |  |  | 1,688 | 2,267 | 12,945
Other operating expenses |  |  |  |  |  |  |  |  | 0 | 1,341 | 2,180
Total expenses |  |  |  |  |  |  |  |  | 1,688 | 3,608 | 15,125
Income before income taxes |  |  |  |  |  |  |  |  | 123 | (4,063) | (12,754)
Income tax (benefit) expense |  |  |  |  |  |  |  |  | 1,800 | (684) | (3,507)
Loss before equity in net income of subsidiaries |  |  |  |  |  |  |  |  | (1,677) | (3,379) | (9,247)
Equity in net income of subsidiaries |  |  |  |  |  |  |  |  | 118,588 | 194,543 | 161,445
Net income |  |  |  |  |  |  |  |  | $ 116,911 | $ 191,164 | $ 152,198

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