Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Unaudited Consolidated Statements of Cash Flows [Abstract]
Net cash provided by operating activities	$ 55,235	$ 32,397
Investing activities:
Purchases of available-for-sale investments	(305,130)	(310,398)
Purchases of limited partnership interests	(897)	0
Proceeds from sales or maturities of available-for-sale investments	257,977	286,580
Net sales of short-term investments	500	720
Distributions from limited partnerships	16,313	1,462
Other investing activities	(4,825)	(5,440)
Net cash used in investing activities	(36,062)	(27,076)
Financing activities:
Dividends paid to shareholders	(12,250)	(11,885)
Repurchase of common shares	(1,880)	0
Net cash used in financing activities	(14,130)	(11,885)
Effect of Foreign exchange rates on cash and cash equivalents	510	398
Increase (decrease) in cash and cash equivalents	5,553	(6,166)
Cash and cash equivalents at beginning of period	62,976	73,538
Cash and cash equivalents at end of period	$ 68,529	$ 67,372