Investments (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value 12 months or less	$ 116,112	$ 123,737
Unrealized Losses 12 months or less	(1,844)	(3,332)
Fair Value Longer than 12 months	56,083	42,126
Unrealized Losses Longer than 12 months	(3,651)	(3,142)
Total Fair Value	172,195	165,863
Total Unrealized Losses	(5,495)	(6,474)
Equity Securities [Member]
Fair Value 12 months or less	1,218	4,748
Unrealized Losses 12 months or less	(211)	(323)
Fair Value Longer than 12 months	0	0
Unrealized Losses Longer than 12 months	0	0
Total Fair Value	1,218	4,748
Total Unrealized Losses	(211)	(323)
Debt Securities [Member]
Fair Value 12 months or less	114,894	118,989
Unrealized Losses 12 months or less	(1,633)	(3,009)
Fair Value Longer than 12 months	56,083	42,126
Unrealized Losses Longer than 12 months	(3,651)	(3,142)
Total Fair Value	170,977	161,115
Total Unrealized Losses	(5,284)	(6,151)
US Treasury Securities and Obligation [Member] | Debt Securities [Member]
Fair Value 12 months or less	10,073	0
Unrealized Losses 12 months or less	(5)	0
Fair Value Longer than 12 months	0	0
Unrealized Losses Longer than 12 months	0	0
Total Fair Value	10,073	0
Total Unrealized Losses	(5)	0
Corporate Bond Securities [Member] | Debt Securities [Member]
Fair Value 12 months or less	27,175	21,752
Unrealized Losses 12 months or less	(459)	(869)
Fair Value Longer than 12 months	4,473	2,366
Unrealized Losses Longer than 12 months	(734)	(786)
Total Fair Value	31,648	24,118
Total Unrealized Losses	(1,193)	(1,655)
Collateralized Corporate Bank Loans [Member] | Debt Securities [Member]
Fair Value 12 months or less	55,213	69,717
Unrealized Losses 12 months or less	(914)	(1,917)
Fair Value Longer than 12 months	14,815	19
Unrealized Losses Longer than 12 months	(396)	(3)
Total Fair Value	70,028	69,736
Total Unrealized Losses	(1,310)	(1,920)
Municipal Bonds [Member] | Debt Securities [Member]
Fair Value 12 months or less	21,745	26,780
Unrealized Losses 12 months or less	(245)	(196)
Fair Value Longer than 12 months	36,689	39,741
Unrealized Losses Longer than 12 months	(2,520)	(2,353)
Total Fair Value	58,434	66,521
Total Unrealized Losses	(2,765)	(2,549)
Collateralized Mortgage Backed Securities [Member] | Debt Securities [Member]
Fair Value 12 months or less	688	740
Unrealized Losses 12 months or less	(10)	(27)
Fair Value Longer than 12 months	106	0
Unrealized Losses Longer than 12 months	(1)	0
Total Fair Value	794	740
Total Unrealized Losses	(11)	(27)
Equity Securities Financial Services [Member] | Equity Securities [Member]
Fair Value 12 months or less	90	1,789
Unrealized Losses 12 months or less	(3)	(260)
Fair Value Longer than 12 months	0	0
Unrealized Losses Longer than 12 months	0	0
Total Fair Value	90	1,789
Total Unrealized Losses	(3)	(260)
Equity Securities, Other [Member] | Equity Securities [Member]
Fair Value 12 months or less	1,128	2,959
Unrealized Losses 12 months or less	(208)	(63)
Fair Value Longer than 12 months	0	0
Unrealized Losses Longer than 12 months	0	0
Total Fair Value	1,128	2,959
Total Unrealized Losses	$ (208)	$ (63)