Investments (Mortgage Loans and Valuation Allowance by Portfolio Segment) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Mortgage Loans on Real Estate [Line Items]
Unpaid Principal Balance	$ 120	$ 126
Recorded Investment	117	123
Valuation Allowances	22	26
Unpaid Principal Balance	176	155
Recorded Investment	172	150
Recorded Investment	61,834	59,562
Valuation Allowances	293	279
Carrying Value	267	247
Commercial
Mortgage Loans on Real Estate [Line Items]
Unpaid Principal Balance	69	75
Recorded Investment	69	75
Valuation Allowances	20	24
Unpaid Principal Balance	98	101
Recorded Investment	98	100
Recorded Investment	41,997	40,913
Valuation Allowances	205	200
Carrying Value	147	151
Agricultural
Mortgage Loans on Real Estate [Line Items]
Unpaid Principal Balance	51	51
Recorded Investment	48	48
Valuation Allowances	2	2
Unpaid Principal Balance	16	14
Recorded Investment	16	13
Recorded Investment	12,269	12,317
Valuation Allowances	37	37
Carrying Value	62	59
Residential
Mortgage Loans on Real Estate [Line Items]
Unpaid Principal Balance	0	0
Recorded Investment	0	0
Valuation Allowances	0	0
Unpaid Principal Balance	62	40
Recorded Investment	58	37
Recorded Investment	7,568	6,332
Valuation Allowances	51	42
Carrying Value	$ 58	$ 37

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

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The balance of financing receivables that were collectively evaluated for impairment.

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-Publisher FASB

-Name Accounting Standards Codification

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