Investments in Debt and Equity Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Gross unrealized losses on investments and the fair values of the related securities
Losses, Less than 12 months	$ 557	$ 2,001
Fair Values, Less than 12 months	77,471	103,806
Losses, More than 12 months	25	1,029
Fair Values, More than 12 months	1,106	24,830
Total Losses	582	3,030
Total Fair Values	78,577	128,636
Municipal [Member]
Gross unrealized losses on investments and the fair values of the related securities
Losses, Less than 12 months	9
Fair Values, Less than 12 months	697
Total Losses	9
Total Fair Values	697
Corporate and utilities [Member]
Gross unrealized losses on investments and the fair values of the related securities
Losses, Less than 12 months	1	1,944
Fair Values, Less than 12 months	653	42,851
Losses, More than 12 months		1,029
Fair Values, More than 12 months		24,830
Total Losses	1	2,973
Total Fair Values	653	67,681
Foreign [Member]
Gross unrealized losses on investments and the fair values of the related securities
Losses, Less than 12 months	302	53
Fair Values, Less than 12 months	74,338	59,708
Total Losses	302	53
Total Fair Values	74,338	59,708
Equity securities [Member]
Gross unrealized losses on investments and the fair values of the related securities
Losses, Less than 12 months	245	4
Fair Values, Less than 12 months	1,783	1,247
Losses, More than 12 months	25
Fair Values, More than 12 months	1,106
Total Losses	270	4
Total Fair Values	$ 2,889	$ 1,247