Employee Retirement Benefits (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Oct. 22, 2014 plan	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)	Jun. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Nov. 30, 2012 USD ($)	Jan. 01, 2012 USD ($)	Dec. 31, 2011 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss)		$ (115)	$ 6	$ (23)		$ (38)	$ (1)	$ (13)	$ (57)	$ (75)	$ (50)
Number of unfunded plans | plan					2
Maximum annual contribution credit per employee, percent			3.00%
Defined contribution plan, costs recognized		18	$ 18	19
Multiemployer plans withdrawal obligation												$ 24
Amounts reclassified from accumulated other comprehensive income (loss)		(16)	1
Total equity		$ (2,464)	$ (2,567)	(2,331)		$ (2,779)	$ (2,666)	$ (2,491)	(2,600)	(1,959)	(1,847)			$ (2,118)
Non collectively bargained members
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contribution credit per employee, percent			5.00%
Non collectively bargained members | Minimum
Defined Benefit Plan Disclosure [Line Items]
Service period			120 months
Collectively bargained members
Defined Benefit Plan Disclosure [Line Items]
Maximum annual contribution credit per employee, percent			6.50%
Key officer postretirement car benefit plan
Defined Benefit Plan Disclosure [Line Items]
Benefit period availability, post retirement		15 years
Eligible Age		80 years
Key officer postretirement car benefit plan | Minimum
Defined Benefit Plan Disclosure [Line Items]
Service period		20 years
Retirement age		58 years
U.K. Plan
Defined Benefit Plan Disclosure [Line Items]
Provisions charged to income		$ 10	$ 10	9
U.K. Plan | U.K.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		201
U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 619	563	498
Expected return on plan assets, percent		7.40%
Company contributions		$ 35	20
Pension Benefits - Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		212	207	178
Company contributions		$ 5	5
Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets, percent		7.50%
Discretionary cash contributions to qualified pension plan		$ 5	5
Estimated future contributions		$ 3
Marketable securities | U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		65.00%
Fixed Income Funds | U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		35.00%
Actively Managed Multi-Asset Funds | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		37.50%
Passive Equity Funds | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		27.50%
U.K. Equities | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		45.00%
Passive Bond Funds | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		35.00%
Municipal Bonds | U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 10	11
Municipal Bonds | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		70.00%
Corporate Bonds | U.S. Plan
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 123	106
Corporate Bonds | Pension Benefits - Non-U.S. | U.K.
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations		30.00%
Forecast
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match, first three percent	100.00%
Employer matching contribution, percent of match, remaining two percent	50.00%
Restatement Adjustment
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss)			(1)	4					$ (6)	(2)	1
Total equity			204	155						$ 180	$ 167
Pension and Other Post-Employment Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss)		$ (101)	(58)	(110)
Amounts reclassified from accumulated other comprehensive income (loss)		(9)	0
Accumulated Adjustments, Other
Defined Benefit Plan Disclosure [Line Items]
Reclassification from ACOI before tax		(27)
Amounts reclassified from accumulated other comprehensive income (loss)		17
Adjustment for Change in Accounting Principle
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive income (loss)		(15)	$ (6)	$ 1
Reclassification from ACOI before tax		(24)
Amounts reclassified from accumulated other comprehensive income (loss)		15
Adjustment for Change in Accounting Principle | Restatement Adjustment
Defined Benefit Plan Disclosure [Line Items]
Total equity													$ (4)
Prior Period Misstatements Corrected in Current Period
Defined Benefit Plan Disclosure [Line Items]
Reclassification from ACOI before tax		(3)
Amounts reclassified from accumulated other comprehensive income (loss)		$ 2
Prior Period Misstatements Corrected in Current Period | Restatement Adjustment
Defined Benefit Plan Disclosure [Line Items]
Total equity													$ 2