Investments (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary of realized and unrealized gains and losses
Total gains	$ 9,851	$ 12,553	$ 2,434
Total losses	(158)	(1,587)	(183)
Net realized gains (losses)	9,693	10,966	2,251
Net change in unrealized gains	9,756	10,552	15,599
Fixed maturity [Member]
Summary of realized and unrealized gains and losses
Total gains	9,851	12,553	2,144
Total losses	(158)	(1,587)	(183)
Net change in unrealized gains	9,660	10,706	15,512
Common stock [Member]
Summary of realized and unrealized gains and losses
Total gains			274
Total losses
Net change in unrealized gains	(53)	(175)	63
Preferred stock [Member]
Summary of realized and unrealized gains and losses
Total gains			16
Total losses
Net change in unrealized gains	$ 149	$ 21	$ 24