Derivatives and Hedging Activities (Option Rec/Pay) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014
Summary of option premiums payable and receivable
Premiums Payable	$ 1,801
Premiums Receivable	368
2014
Summary of option premiums payable and receivable
Premiums Payable	185	[1]
Premiums Receivable	56	[1]
2015
Summary of option premiums payable and receivable
Premiums Payable	355
Premiums Receivable	67
2016
Summary of option premiums payable and receivable
Premiums Payable	313
Premiums Receivable	54
2017
Summary of option premiums payable and receivable
Premiums Payable	242
Premiums Receivable	53
2018
Summary of option premiums payable and receivable
Premiums Payable	194
Premiums Receivable	56
2019-2026
Summary of option premiums payable and receivable
Premiums Payable	512
Premiums Receivable	$ 82

[1] 2014 amounts represent the amounts payable and receivable for the period from July 1, 2014 to December 31, 2014.