Summary of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 Subsidiary	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Line Items]
Number of insurance companies	13
Percentage of direct premiums written as private passenger automobile lines of insurance	80.00%	80.00%	80.00%
Percentage of private passenger automobile premiums written in California	78.00%	77.00%	77.00%
Percentage by which dividend income on non redeemable preferred stock, partnership, common stock is partially tax-sheltered	70.00%
Other liabilities	$ 153,972,000	$ 149,007,000
Marketable securities, fixed maturities	42,800,000
Marketable securities, equity securities	11,300,000
Insurance companies security deposits	16,000,000	18,000,000
Deferred policy acquisition cost amortization	477,788,000	481,721,000	505,565,000
Advertising expenses	19,000,000	21,000,000	30,000,000
Impairment charges	0	0	0
Goodwill impairment loss	0
Premiums written, net	2,650,000,000	2,580,000,000	2,560,000,000
Broker direct premiums percentage account	2.00%	2.00%	2.00%
Options Granted Prior To 2008 [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Option vesting term, years	4 years
Options Granted Prior To 2008 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Option vesting term, years	5 years
Options Granted Subsequent To January 1, 2008 [Member]
Summary Of Significant Accounting Policies [Line Items]
Option vesting term, years	4 years
Building [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, in years	30 years
Building [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, in years	40 years
Furniture Equipment And Purchase Software [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, in years	3 years
Furniture Equipment And Purchase Software [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, in years	7 years
Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Useful life, in years	5 years
Secured Note No1 [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt instrument, fair value	120,000,000
Secured Note No2 [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt instrument, fair value	20,000,000
Call Option [Member]
Summary Of Significant Accounting Policies [Line Items]
Other liabilities	$ 200,000	$ 700,000