Retirement Plan Benefits - Pension Plan Investments at Fair Value Represented 5% or More of Pension Plan Net Assets (Details) (Pension Plan Net Assets, Credit Concentration Risk, USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	$ 385	$ 376
EB Daily Valued Small Cap Stock Index Fund
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	30	26
EB Daily Valued Stock Index Fund
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	104	86
EB Daily Valued International Stock Index Fund
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	30	26
EB Long Term Government Bond Index
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	40	46
EB Long Term Credit Bond Index
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	63	68
Corporate Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Pension plan investments, at fair value	$ 118	$ 124