Consolidated Statements of Financial Position (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investments:
Fixed maturities available-for-sale, cost	$ 559,736	$ 484,809
Fixed maturities held-to-maturity, fair value	193,739	230,093
Available-for-sale equity securities, amortized cost basis	52,744	45,599
Real estate held for investment, accumulated depreciation	1,287	1,149
Due premiums, allowance for doubtful accounts	$ 1,345	$ 1,698
Common Stock Class A [Member]
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	52,215,852	52,089,189
Common stock, shares outstanding (in shares)	52,215,852	52,089,189
Common stock, shares in treasury (in shares)	3,135,738	3,135,738
Common Stock Class B [Member]
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.00	$ 0.00
Common stock, shares authorized (in shares)	2,000,000	2,000,000
Common stock, shares issued (in shares)	1,001,714	1,001,714
Common stock, shares outstanding (in shares)	1,001,714	1,001,714