Fair Value Measurements (Quantitative Information Used As Level 3 Inputs) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016 USD ($) $ / bond	Dec. 31, 2015 USD ($)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Other assets and (liabilities)	$ 980	$ 3,463
Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Assets, fair value	(2,680)
Other assets and (liabilities)	(2,680)
Assumed reinsurance contract | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Liabilities, fair value	$ (1,302)
Assumed reinsurance contract | Low | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Bond price | $ / bond	97.61
Assumed reinsurance contract | Maximum | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Bond price | $ / bond	100.02
Assumed reinsurance contract | Weighted Average or Actual | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Bond price | $ / bond	99.02
Liquidity discount	1.30%
Assumed and ceded (re)insurance contract | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Liabilities, fair value	$ (1,378)
Assumed and ceded (re)insurance contract | Low | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Contract period	6 months 10 days
Assumed and ceded (re)insurance contract | Maximum | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Contract period	3 years 5 days
Assumed and ceded (re)insurance contract | Weighted Average or Actual | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Net undiscounted cash flows	$ (10,753)
Expected loss ratio	0.10%
Net acquisition expense ratio	23.00%
Contract period	2 years 2 months 7 days
Discount rate	0.70%
Assumed and ceded (re)insurance contracts | Internal Valuation Model Valuation Technique | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
Liabilities, fair value	$ (2,680)