Investments (Schedule Of Available-For-Sale Securities Whose Value Is Below Amortized Cost) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015 security		Dec. 31, 2014 security
Available For Sale Securities In Unrealized Loss Position With Loss Severity Greater Than 20 Percent [Line Items]
Fair Value	$ 89,621		$ 87,069
Continuous Unrealized Loss Position, Total	8,028		10,962
Fair Value Decline, Greater Than 20% [Member]
Available For Sale Securities In Unrealized Loss Position With Loss Severity Greater Than 20 Percent [Line Items]
Fair Value	320		298
Gross Unrealized Losses	95		98
Gross Unrealized OTTI	73		59
Number of Securities	111	[1]	97	[1]
Fair Value Decline, Greater Than 20% [Member] | Less Than Six Months [Member]
Available For Sale Securities In Unrealized Loss Position With Loss Severity Greater Than 20 Percent [Line Items]
Fair Value	147		48
Gross Unrealized Losses	42		19
Gross Unrealized OTTI	23
Number of Securities	41	[1]	12	[1]
Fair Value Decline, Greater Than 20% [Member] | Six Months Or Greater, But Less Than Nine Months [Member]
Available For Sale Securities In Unrealized Loss Position With Loss Severity Greater Than 20 Percent [Line Items]
Fair Value	40		8
Gross Unrealized Losses	20		7
Gross Unrealized OTTI	2
Number of Securities	9	[1]	3	[1]
Fair Value Decline, Greater Than 20% [Member] | Twelve Months Or Greater [Member]
Available For Sale Securities In Unrealized Loss Position With Loss Severity Greater Than 20 Percent [Line Items]
Fair Value	133		242
Gross Unrealized Losses	33		72
Gross Unrealized OTTI	$ 48		$ 59
Number of Securities	61	[1]	82	[1]

[1] We may reflect a security in more than one aging category based on various purchase dates.