Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$ 295,271
Other Comprehensive Income Loss Net Of Tax	(27,171)	16,636
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	268,100
Net realized investment gain	8,570	171
Income tax expense	2,999	60
Total reclassifications	5,571	111
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	282,503
Other Comprehensive Income Loss Net Of Tax	(25,639)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	256,864
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	12,768
Other Comprehensive Income Loss Net Of Tax	(1,532)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	11,236
Accumulated other comprehensive income
Other Comprehensive Income Loss Net Of Tax	$ (27,171)