Summary of Significant Accounting Policies (Life Settlement Contracts) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
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	50
Life settlement contracts, fair value method, number of contracts, maturing in year five	50
Life settlement contracts, fair value method, number of contracts, maturing after year five	318
Life settlement contracts, fair value method, number of contracts	588
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	9
Life settlement contracts, fair value, maturing in year four	7
Life settlement contracts, fair value, maturing in year five	6
Life settlement contracts, fair value, maturing after year five	39
Life settlement contracts, fair value	82	88
Life settlement contracts, fair value method, face value, maturing in next twelve months	37
Life settlement contracts, fair value method, face value, maturing in year two	33
Life settlement contracts, fair value method, face value, maturing in year three	30
Life settlement contracts, fair value method, face value, maturing in year four	26
Life settlement contracts, fair value method, face value, maturing in year five	26
Life settlement contracts, fair value method, face value, maturing after year five	187
Life settlement contracts, fair value method, face value	$ 339