Pension Plans, Retirement Benefits and Savings Plans (details) - Additional Pension Disclosures - Change in Assumptions for Pension Plans and Postretirement Benefit Plans [Member] $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Impact of Change in Estimation Approach [Member]
Change in Accounting Estimate
Reduction to service cost	$ 1
Reduction to interest cost	$ 8
Current Estimation Approach [Member] | Qualified Domestic Pension Plan [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	4.77%
Weighted average discount rate used to measure interest cost (percent)	3.64%
Current Estimation Approach [Member] | Nonqualified Domestic Pension Plan [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	4.53%
Weighted average discount rate used to measure interest cost (percent)	3.47%
Current Estimation Approach [Member] | Domestic Postretirement Benefit Plans [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	0.00%
Weighted average discount rate used to measure interest cost (percent)	3.53%
Prior Estimation Approach [Member] | Qualified Domestic Pension Plan [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	4.50%
Weighted average discount rate used to measure interest cost (percent)	4.50%
Prior Estimation Approach [Member] | Nonqualified Domestic Pension Plan [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	4.37%
Weighted average discount rate used to measure interest cost (percent)	4.37%
Prior Estimation Approach [Member] | Domestic Postretirement Benefit Plans [Member]
Change in Accounting Estimate
Weighted average discount rate used to measure service cost (percent)	4.35%
Weighted average discount rate used to measure interest cost (percent)	4.35%