Investments (Investment Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments [Line Items]
Total investment income	$ 128,877	$ 135,461	$ 143,511
Less: Investment expense	(4,339)	(3,565)	(2,564)
Net investment income	124,538	131,896	140,947
Fixed Maturity Securities [Member]
Investments [Line Items]
Total investment income	107,926	117,557	130,895
Equity Securities [Member]
Investments [Line Items]
Total investment income	18,249	15,831	10,869
Short-Term Investments [Member]
Investments [Line Items]
Total investment income	$ 2,702	$ 2,073	$ 1,747