Investments (Details 3) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012 Securities	Dec. 31, 2011 Securities
Securities in a continuous unrealized loss position for greater than 12 months
Number of Securities	5	4
Gross unrealized losses at fair value	$ 1,737	$ 2,951
Gross Unrealized Losses	(141)	(202)
Less than or equal to 10% [Member]
Securities in a continuous unrealized loss position for greater than 12 months
Number of Securities	4	3
Gross unrealized losses at fair value	1,544	2,760
Gross Unrealized Losses	(38)	(92)
Greater than 10% [Member]
Securities in a continuous unrealized loss position for greater than 12 months
Number of Securities	1	1
Gross unrealized losses at fair value	193	191
Gross Unrealized Losses	$ (103)	$ (110)