Investments (Details 4) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cumulative credit loss
Beginning of period	$ 3,957	$ 4,518
New credit losses	2
Losses related to securities sold or paid down during the period	(1,082)	(561)
End of period	$ 2,877	$ 3,957