Investments in Debt and Equity Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	$ 456	$ 2,001
Fair Values, Less than 12 months	78,234	103,806
Losses, More than 12 months	108	1,029
Fair Values, More than 12 months	8,014	24,830
Total Losses	564	3,030
Total Fair Values	86,248	128,636
Municipal [Member]
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	0
Fair Values, Less than 12 months	400
Losses, More than 12 months	0
Fair Values, More than 12 months	0
Total Losses	0
Total Fair Values	400
Corporate and utilities [Member]
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	150	1,944
Fair Values, Less than 12 months	11,916	42,851
Losses, More than 12 months	94	1,029
Fair Values, More than 12 months	6,185	24,830
Total Losses	244	2,973
Total Fair Values	18,101	67,681
Foreign [Member]
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	164	53
Fair Values, Less than 12 months	64,573	59,708
Losses, More than 12 months	0	0
Fair Values, More than 12 months	0	0
Total Losses	164	53
Total Fair Values	64,573	59,708
U.S. Government [Member]
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	0
Fair Values, Less than 12 months	510
Losses, More than 12 months	0
Fair Values, More than 12 months	0
Total Losses	0
Total Fair Values	510
Equity securities [Member]
Gross unrealized losses on investments and the fair values of the related securities[Abstract]
Losses, Less than 12 months	142	4
Fair Values, Less than 12 months	835	1,247
Losses, More than 12 months	14	0
Fair Values, More than 12 months	1,829	0
Total Losses	156	4
Total Fair Values	$ 2,664	$ 1,247