Investments (Reclassifications of AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flow hedges - Currency/Interest rate
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	$ 2,070	$ 148	$ (95)
Net unrealized investment gains (losses) on available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	2,761	14,558	8,900
Accumulated Other Comprehensive Income (Loss) Related To Net Unrealized Investment Gains (Losses)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	4,831	14,706	8,805
Total reclassifications for the period
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total reclassifications for the period	$ 4,831	$ 14,706	$ 8,805