Retirement Plans and Other Retiree Benefits (Details 1) - USD ($) $ in Millions		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Percentage Of Fixed Income Portfolio Invested In Us Treasury Or Agency Securities		50.00%		50.00%
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Percentage Of Equity Securities Invested In Employer Securities		7.00%		7.00%
Defined Benefit Plan, Fair Value of Plan Assets		$ 1,624		$ 1,771		$ 1,736
United States Pension Plan of US Entity [Member] | Cash & cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		16		48
United States Pension Plan of US Entity [Member] | U.S. common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		126		130
United States Pension Plan of US Entity [Member] | International common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
United States Pension Plan of US Entity [Member] | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	718		625
United States Pension Plan of US Entity [Member] | Developed market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	321		352
United States Pension Plan of US Entity [Member] | Emerging market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	28		32
United States Pension Plan of US Entity [Member] | Other common stock funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	123		118
United States Pension Plan of US Entity [Member] | Fixed income funds: U.S. or foreign government and agency securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	25		115
United States Pension Plan of US Entity [Member] | Fixed income funds: investment grade corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	113		168
United States Pension Plan of US Entity [Member] | Fixed income funds: high yield corporate bonds and other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	114		136
United States Pension Plan of US Entity [Member] | Guaranteed investment contracts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	1		1
United States Pension Plan of US Entity [Member] | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	39		46
International Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		520		552		558
International Pension Benefits [Member] | Cash & cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		13		10
International Pension Benefits [Member] | U.S. common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		3		3
International Pension Benefits [Member] | International common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		2
International Pension Benefits [Member] | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	0		0
International Pension Benefits [Member] | Developed market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	185		193
International Pension Benefits [Member] | Emerging market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	8		8
International Pension Benefits [Member] | Other common stock funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	23		27
International Pension Benefits [Member] | Fixed income funds: U.S. or foreign government and agency securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	102		107
International Pension Benefits [Member] | Fixed income funds: investment grade corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	68		75
International Pension Benefits [Member] | Fixed income funds: high yield corporate bonds and other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	47		54
International Pension Benefits [Member] | Guaranteed investment contracts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	52		54
International Pension Benefits [Member] | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		19	[4]	19	[4]	21
Other Retiree Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		14		41		$ 41
Other Retiree Benefit Plans [Member] | Cash & cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		1
Other Retiree Benefit Plans [Member] | U.S. common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		1		3
Other Retiree Benefit Plans [Member] | International common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets		0		0
Other Retiree Benefit Plans [Member] | Fixed income securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[1]	6		13
Other Retiree Benefit Plans [Member] | Developed market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	3		9
Other Retiree Benefit Plans [Member] | Emerging market equity index funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	0		1
Other Retiree Benefit Plans [Member] | Other common stock funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	1		3
Other Retiree Benefit Plans [Member] | Fixed income funds: U.S. or foreign government and agency securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	0		3
Other Retiree Benefit Plans [Member] | Fixed income funds: investment grade corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	1		4
Other Retiree Benefit Plans [Member] | Fixed income funds: high yield corporate bonds and other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[2]	1		3
Other Retiree Benefit Plans [Member] | Guaranteed investment contracts | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[3]	0		0
Other Retiree Benefit Plans [Member] | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	[4]	$ 1		$ 1

[1] The fixed income securities are traded over the counter and certain of these securities lack daily pricing or liquidity and as such are classified as Level 2. As of December 31, 2015 and 2014, approximately 50% of the fixed income portfolio was invested in U.S. treasury or agency securities, with the remainder invested in other government bonds and corporate bonds.

[2] Interests in common/collective trust funds are valued using the net asset value (“NAV”) per unit in each fund. The NAV is based on the value of the underlying investments owned by each trust, minus its liabilities, divided by the number of shares outstanding.

[3] The guaranteed investment contracts (“GICs”) represent contracts with insurance companies measured at the cash surrender value of each contract. The Level 2 valuation reflects that the cash surrender value is based principally on a referenced pool of investment funds with active redemption.

[4] Real estate is valued using the NAV per unit of funds that are invested in real estate property. The investment value of the real estate property is determined quarterly using independent market appraisals as determined by the investment manager. Since the appraisals include unobservable inputs, these investments are classified as Level 3. These unobservable inputs may include items such as annual gross rents, projected vacancy rates, collection losses and recovery rates, yield rates, growth assumptions and risk adjusted discount rates.