Summary of Significant Accounting Policies (Life Settlement Contracts) (Details) $ in Millions	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Life Settlement Contracts, Fair Value Method, Number of Contracts, Fiscal Year Maturity [Abstract]
Life settlement contracts, fair value method, number of contracts, maturing in next twelve months	60
Life settlement contracts, fair value method, number of contracts, maturing in year two	60
Life settlement contracts, fair value method, number of contracts, maturing in year three	50
Life settlement contracts, fair value method, number of contracts, maturing in year four	40
Life settlement contracts, fair value method, number of contracts, maturing in year five	40
Life settlement contracts, fair value method, number of contracts, maturing after year five	300
Life settlement contracts, fair value method, number of contracts	550
Life settlement contracts, fair value, maturing in next twelve months	$ 11
Life settlement contracts, fair value, maturing in year two	10
Life settlement contracts, fair value, maturing in year three	8
Life settlement contracts, fair value, maturing in year four	6
Life settlement contracts, fair value, maturing in year five	5
Life settlement contracts, fair value, maturing after year five	34
Life settlement contracts, fair value	74	$ 82
Life settlement contracts, fair value method, face value, maturing in next twelve months	35
Life settlement contracts, fair value method, face value, maturing in year two	31
Life settlement contracts, fair value method, face value, maturing in year three	27
Life settlement contracts, fair value method, face value, maturing in year four	24
Life settlement contracts, fair value method, face value, maturing in year five	21
Life settlement contracts, fair value method, face value, maturing after year five	167
Life settlement contracts, fair value method, face value	$ 305