Retrocession Arrangements and Reinsurance Ceded Receivables (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Effects of Reinsurance [Line Items]
Reinsurance ceded receivables	$ 594,794,000	$ 594,515,000
Reinsurance Claims Recoverables	141,700,000	134,100,000
Claims Recoverable From Retrocessionaires Past Due	7,500,000	4,200,000
Reinsurance Recoverables Ceded Credit Risk	$ 358,900,000	$ 359,200,000
Reinsurance Recoverables, Percentage of Total	60.30%	60.40%
AM Best, A- Rating [Member]
Effects of Reinsurance [Line Items]
Ceded Credit Risk, Disclosure	“A- (excellent)”	“A- (excellent)”