Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Balance Sheet Related Disclosures [Abstract]
Held-to-maturity securities, at fair value	$ 1,883	$ 4,161
Available-for-sale securities, at amortized cost	2,667,040	2,562,786
Equity securities, at amortized cost	68,959	68,559
Trading securities, at amortized cost	13,547	13,429
Allowance for doubtful accounts	849	825
Property and equipment accumulated depreciation	$ 34,891	$ 35,248
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	25,417,390	25,505,350
Common stock, shares outstanding	25,417,390	25,505,350