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Summary of Significant Accounting Policies (Narrative) (Details) (USD $) | 12 Months Ended |  | 12 Months Ended | 0 Months Ended |  |  |  |  |  |  |
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Dec. 31, 2013 Subsidiary | Dec. 31, 2012 | Dec. 31, 2011 | Sep. 30, 2013 | Dec. 31, 2013 Options Granted Prior To 2008 [Member] Minimum [Member] | Dec. 31, 2013 Options Granted Prior To 2008 [Member] Maximum [Member] | Dec. 31, 2013 Options Granted Subsequent To January 1, 2008 [Member] | Dec. 31, 2013 Building [Member] Minimum [Member] | Dec. 31, 2013 Building [Member] Maximum [Member] | Dec. 31, 2013 Furniture Equipment And Purchase Software [Member] Minimum [Member] | Dec. 31, 2013 Furniture Equipment And Purchase Software [Member] Maximum [Member] | Dec. 31, 2013 Software [Member] | Aug. 09, 2013 Swap [Member] | Dec. 31, 2013 Swap [Member] | Sep. 30, 2013 Swap [Member] | Aug. 09, 2013 LIBOR [Member] Swap [Member] | Dec. 31, 2013 Secured Note No1 [Member] | Dec. 31, 2013 Secured Note No2 [Member] | Dec. 31, 2013 Call Option [Member] | Dec. 31, 2012 Call Option [Member] | Dec. 31, 2013 Unsecured Debt [Member] | Dec. 31, 2012 Unsecured Debt [Member]
Summary Of Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of insurance companies | 13 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of direct premiums written as private passenger automobile lines of insurance | 79.10% | 79.00% | 80.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of private passenger automobile premiums written in California | 81.00% | 78.00% | 77.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage by which dividend income on non redeemable preferred stock, partnership, common stock is partially tax-sheltered | 70.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other liabilities | $ 170,665,000 | $ 153,972,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000 | $ 200,000 |  |
Marketable securities, fixed maturities | 4,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Marketable securities, equity securities | 12,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, fair value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 120,000,000 | 20,000,000 |  |  | 50,000,000 | 0
Term of swap agreement |  |  |  |  |  |  |  |  |  |  |  |  | 3 years |  |  |  |  |  |  |  |  |
Basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.20% |  |  |  |  |  |
Notional amount | 149,000,000 |  |  | 149,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Swap agreement collateral |  |  |  |  |  |  |  |  |  |  |  |  |  | 40,000,000 | 40,000,000 |  |  |  |  |  |  |
Insurance companies security deposits | 17,000,000 | 16,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred policy acquisition cost amortization | 505,517,000 | 477,788,000 | 481,721,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Advertising expenses | 20,000,000 | 19,000,000 | 21,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Useful life, in years |  |  |  |  |  |  |  | 30 years | 40 years | 3 years | 7 years | 5 years |  |  |  |  |  |  |  |  |  |
Impairment charges | 0 | 0 | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Goodwill impairment loss | 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Premiums written, net | $ 2,730,000,000 | $ 2,650,000,000 | $ 2,580,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Broker direct premiums percentage account |  | 2.00% | 2.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Option vesting term, years |  |  |  |  | 4 years | 5 years | 4 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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