Employee Benefits - Cash Flows Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($)
U.S. Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected employer contributions during next fiscal year	$ 79
U.K. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected employer contributions during next fiscal year	54
Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected employer contributions during next fiscal year	$ 17