Employee Benefit Plans - Schedule of Asset Categories of U.S. Pension Plan (Details) - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		$ 595	$ 648	$ 617
Cash and Cash Equivalents | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		16	3
Fixed Income | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[1]	109	125
Non-U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[2]	129	148
U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[3]	129	169
Hedge Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[4]	152	164
Real Estate Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[5]	10	10
Real Estate Investment Trust Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		9	8
Private Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[6]	41	21
Level 1 inputs | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		43	30
Level 1 inputs | Cash and Cash Equivalents | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		12	0
Level 1 inputs | Fixed Income | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[1]	0	0
Level 1 inputs | Non-U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[2]	31	30
Level 1 inputs | U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[3]	0	0
Level 1 inputs | Hedge Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[4]	0	0
Level 1 inputs | Real Estate Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[5]	0	0
Level 1 inputs | Real Estate Investment Trust Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		0	0
Level 1 inputs | Private Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[6]	0	0
Level 2 inputs | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		349	423
Level 2 inputs | Cash and Cash Equivalents | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		4	3
Level 2 inputs | Fixed Income | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[1]	109	125
Level 2 inputs | Non-U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[2]	98	118
Level 2 inputs | U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[3]	129	169
Level 2 inputs | Hedge Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[4]	0	0
Level 2 inputs | Real Estate Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[5]	0	0
Level 2 inputs | Real Estate Investment Trust Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		9	8
Level 2 inputs | Private Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[6]	0	0
Level 3 inputs | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		203	195
Level 3 inputs | Cash and Cash Equivalents | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		0	0
Level 3 inputs | Fixed Income | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[1]	0	0
Level 3 inputs | Non-U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[2]	0	0
Level 3 inputs | U.S. Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[3]	0	0
Level 3 inputs | Hedge Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[4]	152	164
Level 3 inputs | Real Estate Funds | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[5]	10	10
Level 3 inputs | Real Estate Investment Trust Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value		0	0
Level 3 inputs | Private Equity | United States Pension Plan of US Entity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair values of the plan assets by asset category and by levels of fair value	[6]	$ 41	$ 21
US Treasury and Government [Member] | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		29.00%
Government agencies | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		24.00%
Fixed Income Funds [Member] | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		20.00%
Corporate Bond Securities [Member] | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		11.00%
Government mortgage-backed securities | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		11.00%
Asset-backed securities | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		3.00%
Cash and Other Securities | Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations		2.00%

[1] A multi-manager strategy investing in fixed income securities and funds. The current allocation includes: 29% in government bonds; 24% in government agencies; 20% in unconstrained bond funds; 11% in corporate bonds; 11% in government mortgage-backed securities; 3% in asset-backed securities; and 2% in cash and other securities.

[2] Multi-manager strategy investing in common stocks of non-U.S. listed companies using both value and growth approaches.

[3] Multi-manager strategy investing in common stocks of U.S. listed companies using value and growth approaches.

[4] Strategies taking long and short positions in equities, fixed income securities, currencies and derivative contracts.

[5] Strategy investing in the global private real estate secondary market using a value-based investment approach.

[6] Partnership making opportunistic investments on a global basis across asset classes, capital structures and geographies.