Consolidated Balance Sheets (Parenthetical) $ in Millions	Sep. 30, 2016 USD ($) shares	Dec. 31, 2015 USD ($) shares
Statement of Financial Position [Abstract]
Available for sale, at amortized cost	$ 78,630	$ 43,149
Fixed maturities available for sale, hybrid financial instruments	5	31
Held to maturity, at Fair Value	11,366	8,552
Equity securities, at cost	695	441
Other investments, cost	$ 4,170	$ 2,993
Common Shares, shares issued | shares	479,783,864	342,832,412
Common Shares, shares outstanding | shares	465,286,110	324,563,441
Common Shares in treasury, shares | shares	14,497,754	18,268,971