Employee Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Components of net periodic cost (income)
Savings plan expenses	$ 4	$ 3
Pension
Components of net periodic cost (income)
Interest cost	7	2
Expected return on plan assets	(9)	(3)
Amortization of net loss	0	1
Net periodic cost (income)	(2)	0
Qualified Pension Plan
Components of net periodic cost (income)
Cash contributions	1	1
Estimated employer contributions in current year	10
Non Qualified Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Number of pension plans	2
General and Administrative Expense | Health Care and Life
Components of net periodic cost (income)
Credit to expense s a result of plan amendments	$ 13