Claim Liabilities and Claim Adjustment Expenses, Supplementary Information about Average Percentage Payout of Incurred Claims by Age (Details) - Property and Casualty [Member]
Dec. 31, 2016
Average Annual Percentage Payout of Incurred Claims by Age, Net of Reinsurance [Abstract]  
2007 45.60%
2008 21.60%
2009 11.90%
2010 7.10%
2011 4.80%
2012 2.90%
2013 1.50%
2014 0.70%
2015 0.60%
2016 0.70%