Benefit Plans Schedule of Allocation of Plan Assets (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 45	[1]	$ 35	[1]	$ 33
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		1
Equity Securities | Commingled Equity Funds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	7		5
Debt Securities | Government Bonds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	31		28
Real Estate
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2		1
Other Pension Investments
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 5		$ 0

[1] Fair values are determined based on valuation inputs categorized as Level 1, 2 or 3 (see Note 4. Significant Accounting Policies—Fair Value). All investment plan assets are valued using Level 1 or Level 2 inputs.