Unaudited Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Unaudited Consolidated Statements of Cash Flows [Abstract]
Net cash provided by operating activities	$ 11,666	$ 6,621
Investing activities:
Purchases of available-for-sale investments	(104,714)	(100,022)
Purchases of limited partnership interests	(1,538)	0
Proceeds from sales or maturities of available-for-sale investments	78,829	96,173
Net sales (purchases) of short-term investments	382	(330)
Other investing activities	3,552	(459)
Net cash used in investing activities	(23,489)	(4,638)
Financing activities:
Dividends paid to shareholders	(3,749)	(3,722)
Repayment on line of credit	0	(5,000)
Net cash used in financing activities	(3,749)	(8,722)
Effect of foreign exchange rates on cash and cash equivalents	204	227
Decrease in cash and cash equivalents	(15,368)	(6,512)
Cash and cash equivalents at beginning of period	89,726	38,223
Cash and cash equivalents at end of period	$ 74,358	$ 31,711