Unaudited Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Unaudited Consolidated Statements of Cash Flows [Abstract]
Net cash provided by operating activities	$ 24,242	$ 44,589
Investing activities:
Purchases of available-for-sale investments	(268,842)	(258,365)
Purchases of limited partnership interests	(1,538)	0
Proceeds from sales or maturities of available-for-sale investments	230,272	247,322
Net sales (purchases) of short-term investments	95	(919)
Other investing activities	2,113	(1,565)
Net cash used in investing activities	(37,900)	(13,527)
Financing activities:
Dividends paid to shareholders	(11,180)	(11,150)
Repayment on line of credit	0	(5,000)
Net cash used in financing activities	(11,180)	(16,150)
Effect of foreign exchange rates on cash and cash equivalents	343	(421)
Increase (decrease) in cash and cash equivalents	(24,495)	14,491
Cash and cash equivalents at beginning of period	89,726	38,223
Cash and cash equivalents at end of period	$ 65,231	$ 52,714