Supplemental Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Supplemental Information
Income taxes paid	$ 26,354	$ 44,531	$ 126,295	$ 83,979
Interest paid	1,486	1,321	14,808	13,321
Dividends declared but not paid at year end	22,540	16,728	22,540	16,728
Purchases of common stock not paid at end of period	0	6,400	0	6,400
Proceeds from sales of available for sale fixed maturity securities	166,094	75,397	337,895	293,969
Proceeds from sales of equity securities	$ 51,681	$ 5,406	$ 95,989	$ 7,145