Pension and Postretirement Benefit Plans - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015		Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		$ 1,505	$ 1,533
Equity Securities [Member] | US All Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	76	64
Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		102	72
Equity Securities [Member] | US Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		26	20
Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		119	132
Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		66	60
Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		65	64
Fixed Income Securities [Member] | US Core Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	137	136
Fixed Income Securities [Member] | Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		419	471
Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		269	264
Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		25	21
Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	66	75
Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	16	12
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		36	41
Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[5]	10	16
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		73	85
United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1,454	1,493		$ 1,622
Net Asset Value		745	737
United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		102	72
United States Pension Plan of US Entity [Member] | Equity Securities [Member] | EAFE Composite [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		119	132
United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		66	59
United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		65	64
United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Core Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value	[2]	70	71
United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		221	223
United States Pension Plan of US Entity [Member] | Alternative Investment [Member] | Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value	[3]	66	75
United States Pension Plan of US Entity [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Asset Value		36	41
Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		51	40		$ 44
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		102	84
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US All Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[1]	76	64
Fair Value, Inputs, Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | US Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		26	20
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0	1
Fair Value, Inputs, Level 1 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | Emerging Markets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets			1
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		607	672
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Core Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	67	65
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | Corporate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		198	248
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Securities [Member] | US Treasury Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		269	264
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[5]	1	11
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Other securities [Member] | Interest Rate Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1	11
Fair Value, Inputs, Level 2 [Member] | United States Pension Plan of US Entity [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		72	84
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		35	27
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Fixed Income Securities [Member] | Foreign Government Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		25	21
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[5]	9	5
Fair Value, Inputs, Level 2 [Member] | Foreign Pension Plan [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1	1
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		16	12
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Alternative Investment [Member] | Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[4]	16	12
Fair Value, Inputs, Level 3 [Member] | Foreign Pension Plan [Member] | Other securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets				[5]

[1] This category comprises a combination of small-, mid- and large-cap equity stocks that are allocated at the investment manager's discretion. Investments include common and preferred securities as well as equity funds that invest in these instruments.

[2] This category represents a combination of investment grade corporate bonds, sovereign bonds, Yankee bonds, asset-backed securities and U.S. government bonds. Investments include fixed income funds that invest in these instruments.

[3] This category includes fund managers that invest in a well-diversified group of hedge funds where strategies include, but are not limited to, event driven, relative value, long/short market neutral, multistrategy and global macro. Investments may be made directly or through pooled funds.

[4] This category comprises contracts placed with insurance companies where the underlying assets are invested in fixed interest securities.

[5] Other assets in the U.S. represent interest rate derivatives which had a market value of $1 at December 31, 2016 and $11 at December 31, 2015.